Food Qual Safet

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1. Changes in fruit pigment accumulation, chloroplast development, and transcriptome analysis in the CRISPR/Cas9-mediated knockout of Stay-green 1 (slsgr1) mutant

Liqun Ma, Ni Zeng, Ke Cheng, Jinyan Li, Keru Wang ...

Food Qual Safet 2022, 6 (1): 1-. DOI: 10.1093/fqsafe/fyab029

摘要

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Abstract The green-flesh (gf) mutant of the tomato fruit ripen to a muddy brown color and has been demonstrated previously to be a loss-of-function mutant. Here, we provide more evidence to support this view that SlSGR1 is involved in color change in ripening tomato fruits. Knocking out SlSGR1 expression using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 genome editing strategy showed obviously a muddy brown color with significantly higher chlorophyll and carotenoid content compared with wild-type (WT) fruits. To further verify the role of SlSGR1 in fruit color change, we performed transcriptome deep sequencing (RNA-seq) analysis, where a total of 354 differentially expressed genes (124/230 downregulated/upregulated) were identified between WT and slsgr1. Additionally, the expression of numerous genes associated with photosynthesis and chloroplast function changed significantly when SlSGR1 was knocked out. Taken together, these results indicate that SlSGR1 is involved in color change in ripening fruit via chlorophyll degradation and carotenoid biosynthesis.

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2. Refrigeration temperature enhanced synergistic interaction of curcumin and 460 nm light emitting diode against Staphylococcus saprophyticus at neutral pH

Ziyuan Wang, Lin Han, Jie Liu, Mingfei Yao

Food Qual Safet DOI: 10.1093/fqsafe/fyaa029

摘要

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As considered highly resistant to antibiotics like mecillinam, the rise of Staphylococcus saprophyticus contamination of fresh foods and food processing environments necessitates the development of new antimicrobial approach for food safety control. This study aimed to investigate the synergistic effect of food grade curcumin (CUR) and blue light emitting diode (LED) on S. saprophyticus under different pH (pH 2.2-7.2) and temperatures (4 and 25 °C). The influence of other parameters, including CUR concentration, light dose and incubation time on the inactivation of S. saprophyticus were characterized. Results indicated that the combined treatment of CUR and blue light irradiation significantly (P < 0.05) reduced bacterial counts and the antimicrobial effect was in a CUR concentration and light dose-dependent manner. Moreover, refrigeration temperature (4 °C) significantly (P < 0.05) enhanced the antibacterial effect at neutral pH condition (6.2-7.2), resulting in approximately 6.0 log reductions. Under acidic condition (pH 2.2-5.2), there was no significant difference in bacterial population reduction between treatments at both temperatures. These finding proposed that synergistic interaction of curcumin and 460 nm LED under refrigerated temperature could enhance the inactivation of S. saprophyticus at neutral pH condition.

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3. Using endogenous pigments to recolour roasted green tea

朱宏凯, 张坚强, 刘飞, 陈琳, 叶阳

Food Qual Safet DOI: 10.1093/fqsafe/fyab006

摘要

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Roasted green tea exhibits undesirable dark green that can seriously affect sensory quality, market price, and consumer acceptance. The aim of this work was to propose a method of improving the appearance of the roasted green tea. In this study, rehydration with freeze-drying (RFD) was used to recolour the tea leaves by redistributing the endogenous pigments. The results indicated that the colour of the roasted green tea changed from dark green to bright green after the RFD treatment, the values of L* and b* were significantly increased (P<0.05), and the value of a* was significantly decreased (P<0.05). In addition, the RFD treatment making the yellow–green pigments transfer onto the surface of the tea leaves also induced a change in pigment contents, including chlorophylls, carotenoids, and flavonoid glycosides. The well-defined optimum parameters for the rehydration process were moisture content of tea leaves at 35 per cent, water temperature 25 °C, and a standing time of 1.5 h.

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4. Cold shock treatment alleviates chilling injury in peach fruit by regulating antioxidant capacity and membrane lipid metabolism

Yuqing Ma, Shunqing Hu, Guifang Chen, Yonghua Zheng, Peng Jin

Food Qual Safet 2022, 6 (1): 1-. DOI: 10.1093/fqsafe/fyab026

摘要

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Objectives The work intended to reveal the effect of cold shock (CS) treatment on chilling injury (CI), antioxidant capacity, and membrane fatty acid of peach fruit. Materials and methods Peaches were soaked in ice water (0 °C) for 10 min and stored at 5 °C for 28 days for determination, except CI, and then stored for 3 days at 20 °C, only CI was measured. The electrolyte leakage (EL) was measured by conductivity meter. The activities of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase, catalase, and peroxidase) and key enzymes of membrane lipid metabolism (phospholipase D, lipase, and lipoxygenase) as well as reactive oxygen species (ROS; O2·– and H2O2) were measured with a spectrophotometer. An ELISA kit and gas chromatography were used to determine membrane lipids and membrane fatty acids. The relative gene expression was measured by real-time polymerase chain reaction analysis. Results The results showed that CS treatment effectively delayed CI, suppressed the increase of EL and malondialdehyde content. Meanwhile, CS-treated fruit exhibited lower level of ROS and higher activities of antioxidant enzymes. Furthermore, CS treatment inhibited the activities as well as the relative gene expression of key enzymes in membrane lipid metabolism. CS-treated fruits maintained higher membrane fatty acid unsaturation and lower phosphatidic acid content. Conclusions These results indicated that CS treatment effectively alleviated CI and maintained the integrity of cell membranes by inducing antioxidant-related enzyme activity and maintaining a higher ratio of unsaturated fatty acids to saturated fatty acids.

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5. Optimization of ultrasonic-assisted freezing of Penaeus chinensis by response surface methodology

应宇斌, 向迎春, 刘佳琳, 陈欣, 胡玲萍, Yujin Li, 胡亚芹

Food Qual Safet 2021, 5 (1): 1-9. DOI: 10.1093/fqsafe/fyaa034

摘要

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Objectives

Optimization of ultrasonic-assisted freezing of Penaeus chinensis by response surface methodology was studied in order to (1) obtain frozen Penaeus chinensis of high quality and (2) provide practical guidance for the application of ultrasonic-assisted freezing in Penaeus chinensis.

Materials and Methods

Three independent and major variables were selected, including initial ultrasonic temperature (°C), ultrasonic power (W) and ultrasonic time (s on/2 s off). On the basis of one-factor experiments, 17 groups of experiments were established by response surface methodology according to Box–Behnken design. Using multiple regression analysis the experimental data were fitted into a second-order polynomial equation, which was tested by proper statistical methods.

Results

The optimal ultrasonic conditions were as follows: initial ultrasonic temperature 0 °C, ultrasonic power 180 W, ultrasonic time 5 s on/2 s off. Under the optimization conditions, the time of passing through maximum ice crystal generation zone was 105.500 s, which was very close to the predictive passage time of 101.541 s.

Conclusions

Initial ultrasonic temperature, ultrasonic time and ultrasonic power played an important role in the process of ultrasonic-assisted freezing of Penaeus chinensis. Response surface methodology was used to optimize the three factors in ultrasonic-assisted freezing, which could greatly shorten the time of passing through the maximum ice crystal generation zone and maintain the tissue structure of Penaeus chinensis well.

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6. Effects of decontamination treatment combined with natural chemicals and/or ultra-high pressure on the quality and safety of ready-to-eat wine-pickled mud snails (Bullacta exarata)

邹小欠, 彭思佳, 庞春霞, 王俊豪, Mohamed Hawali Bata Gouda, 杜传来, 余炬波, 罗海波, 姜丽

Food Qual Safet DOI: 10.1093/fqsafe/fyab001

摘要

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Ready-to-eat wine-pickled mud snails (Bullacta exarata) typically host a large number of microorganisms and are frequently contaminated with pathogenic bacteria during processing, resulting in a higher risk for foodborne illness with consumption. In this study, the decontamination effects of different treatment methods, including the use of ultrasonic cleaning (USC), natural chemicals, and ultra-high pressure (UHP), on the quality and safety of pickled mud snails were investigated by assessing the total viable count (TVC), total volatile base nitrogen (TVB-N) content, thiobarbituric acid-reactive substance (TBARS), and pH value of the products after 12 months of storage at –20 °C. Treatment with 200 W USC for 5 min was the most effective approach for reducing TVC in raw mud snails, with a minimal change in food quality. Natural chemical treatment or UHP treatment significantly inhibited the increase in TVC, pH, and TBARS and TVB-N accumulation compared with the control group; however, their combined treatment had no synergistic effect. In contrast, the combined chemical treatment was more effective in inhibiting changes in the above indices in pickled mud snails than UHP treatment alone or combined chemicals+UHP treatment. In addition, the bacterial diversity of pickled mud snails before and after 12 months of storage at –20 °C was determined using Illumina MiSeq sequencing. Our results indicated that USC combined with natural chemicals can be utilized commercially to maintain the quality and safety of pickled mud snails during storage at –20 °C.

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7. Microbiological assessment of street foods at the point of sale in Maputo (Mozambique)

Acácio Salamandane, Ana Carla Silva, Luísa Brito, Manuel Malfeito-Ferreira

Food Qual Safet DOI: 10.1093/fqsafe/fyaa030

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In Mozambique, as in other developing countries, the sale of street food is a source of income for thousands of unemployed families. However, the safety of these types of foods is a serious problem, given their frequent association with food-borne outbreaks. The aim of this study was to assess the microbiological quality and safety of street food sold in the main streets and informal markets of Maputo, the capital of Mozambique. From 83 different vendors selling different types of foods, 83 samples of ready-to-eat (RTE) street food were analyzed. Mesophiles, Escherichia coli and total coliforms were used as quality and hygiene indicators. Listeria monocytogenes, Salmonella and coagulase positive staphylococci were used as food safety indicators. High proportions of unsatisfactory food samples were found in both traditional hot (76.7%) and cold (75%) foods. L. monocytogenes and Salmonella were tested negative in this survey. However, when coagulase positive staphylococci was used as a food safety indicator, approximately 25% (23/83) of the food samples analyzed were classified as unsatisfactory/potentially hazardous. These results, showing that street food sold in Maputo clearly requires adequate sanitary conditions for its preparation and sale, contribute to the development of good manufacturing practices (GMP) for street food in Maputo, Mozambique. This is the first report on the microbiological quality and safety of street food in Mozambique.

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8. Effect of a combined microwave-assisted drying and air drying on improving active nutraceutical compounds, flavor quality, and antioxidant properties of Camellia sinensis L. (cv. Longjing 43) flowers

施林佐, Eunhye Kim, 杨蕾玉, 黄艳梅, 任苧, 李博, 何普明, 屠幼英, 吴媛媛

Food Qual Safet 2021, 5 (1): 1-7. DOI: 10.1093/fqsafe/fyaa040

摘要

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Drying tea flowers into a high-quality product is important to its commodity value. In the present work, a combination of microwave-assisted drying and air drying (MAD-AD) was applied in the processing of fresh tea flowers and its effects on flavor quality, active nutraceutical compounds, and antioxidant capacities were studied. The results showed that compared to air drying and freeze drying tea flowers, the MAD-AD tea flowers had higher amounts of active compounds such as catechins, flavonol glycosides, and triterpenoid saponins, and possessed high antioxidant activities. Moreover, this drying method improved the tea flowers’ color and preserved a more floral fragrance. This combined method could be of interest as an industrial method for drying tea flowers with the benefit of reduced processing time, more reserved active compounds and high quality of products.

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9. Unraveling the acetals as ageing markers of Chinese Highland Qingke Baijiu using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry combined with metabolomics approach

王新磊, 宋学博, 朱琳, 耿晓杰, 郑福平, 赵强忠, 孙啸涛, 赵东瑞, 冯声宝, 赵谋明

Food Qual Safet DOI: 10.1093/fqsafe/fyab014

摘要

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Objectives

The ageing process has a significant impact on the aroma of Chinese Baijiu, which could strengthen the desirable flavor characteristics and reduce the undesirable ones. The aim of this study was to observe the initiation of meaningful changes in volatile fraction and locate the ageing markers during ageing storage of Chinese Highland Qingke Baijiu.

Materials and Methods

Samples of Chinese Qingke Baijiu were aged for 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, and 11 months before analysis. The samples were isolated by liquid–liquid extraction and then analyzed by comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry. The acquired data were processed by untargeted and targeted metabolomics approach to locate the ageing markers.

Results

The untargeted metabolomics analysis (hierarchical clustering analysis, HCA) shows that the chemical composition of Qingke Baijiu presents a statistically significant deviation from the reference scenario after 5 months. Subsequently, supervised statistics analysis (orthogonal partial least squares discrimination analysis) was performed to locate the markers, which changed significantly during ageing. Fifteen markers were located, and seven of them were acetals. Notably, 1,1-diethoxy-propane, 1,1-diethoxy-butane, and 1,1-diethoxy-3-methyl-butane are important contributors to the flavor of Chinese Baijiu. The identified markers were applied for the untargeted metabolomics (HCA), and the results revealed that these markers could divide the Qingke Baijiu into two ageing stages, 0–5 months and 6–11 months.

Conclusion

The results suggest that it is a valuable tool for monitoring the changes of volatile compounds and locating the age markers in Chinese Baijiu.

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10. Melatonin maintains the storage quality of fresh-cut Chinese water chestnuts by regulating phenolic and reactive oxygen species metabolism

Yuhan Xu, Jian Yu, Jinhui Chen, Jiabao Gong, Li Peng ...

Food Qual Safet 2022, 6 (1): 1-.

摘要

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Fresh-cut Chinese water chestnuts (CWCs) are prone to quality deterioration during storage, which does not meet consumer demand. In this study, the effect of exogenous melatonin (5 mmol·L?1) on the quality and potential mechanisms in fresh-cut CWC was investigated. The results showed that melatonin treatment alleviated the cut-surface discoloration of CWCs. Not only did this treatment significantly slow down the increase in browning degree and yellowness (b?) as well as the decrease in lightness (L?), but it also significantly delayed the loss of weight and total soluble solids. Further investigations indicated that melatonin-treated fresh-cut CWCs exhibited significantly lower total phenolics and soluble quinones and suppressed the activities of phenylalanine ammonia-lyase, polyphenol oxidase, and peroxidase. Meanwhile, when fresh-cut CWCs were treated with melatonin, the total flavonoid concentration was significantly decreased compared to the control. Additionally, melatonin significantly inhibited the accumulation of H2O2 and malondialdehyde as well as enhanced the activities of superoxide dismutase and catalase by promoting the production of O2–?. In summary, melatonin treatment may delay the surface discoloration of fresh-cut CWCs by inhibiting phenolic compound metabolism and improving antioxidant capacity, thereby effectively maintaining the quality and prolonging the shelf life of fresh-cut CWCs.

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11. Metabolomics of ginger based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry technology

严辉, 邹冬倩, 周桂生, 余函纹, 李鹏辉, 王天舒, 包贝华, 郭盛, 段金廒

Food Qual Safet 2021, 5 (1): 1-9. DOI: 10.1093/fqsafe/fyaa036

摘要

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Objectives

Dried ginger and ginger are the same type of medicine and food. The differential components of ginger and dried ginger, dried ginger and ginger charcoal were investigated.

Materials and Methods

The experimental materials were divided into three sample groups: the ginger group, dried ginger group, and ginger charcoal group. The ginger group, dried ginger group, and ginger charcoal group were qualitatively analyzed by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The data were processed by Marker View Software. Principal component analysis and orthogonal partial least-square discriminant analysis were performed with SIMCA 13.0 Software. The differential components of the ginger and dried ginger groups as well as the dried ginger and ginger charcoal groups with a variable importance in the projection > 2 (P < 0.05) were identified with PeakView 1.2 Software.

Results

Ten differential components, including 6-gingerol, 8-gingerol, and 10-gingerol, were identified between the ginger group and dried ginger group; 13 differential components, including 6-shogaol, 10-gingerol, and zingiberone, were identified between the dried ginger group and ginger charcoal group.

Conclusions

The main differential components between the ginger and dried ginger groups and the dried ginger and ginger charcoal groups were gingerols and diphenylheptanes. Based on metabolomics analysis of the chemical composition of ginger’s medicinal materials, effects, and other related factors, it is recommended that 6-gingerol, 6-shogaol, and zingiberone should be used as indicative components for the respective quality evaluation of ginger, dried ginger and ginger charcoal. The results of this study may provide a basis for the reasonable quality evaluation of ginger medicinal materials.

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12. Management strategies for aflatoxin risk mitigation in maize, dairy feeds and milk value chains—case study Kenya

Vesa V Joutsjoki, Hannu J Korhonen

Food Qual Safet 2021, 5 (1): 1-11. DOI: 10.1093/fqsafe/fyab005

摘要

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Widespread aflatoxin contamination of a great number of food and feed crops has important implications on global trade and health. Frequent occurrence of aflatoxin in maize and milk poses serious health risks to consumers because these commodities are staple foods in many African countries. This situation calls for development and implementation of rigorous aflatoxin control measures that encompass all value chains, focusing on farms where food and feed-based commodities prone to aflatoxin contamination are cultivated. Good agricultural practices (GAP) have proven to be an effective technology in mitigation and management of the aflatoxin risk under farm conditions. The prevailing global climate change is shown to increase aflatoxin risk in tropical and subtropical regions. Thus, there is an urgent need to devise and apply novel methods to complement GAP and mitigate aflatoxin contamination in the feed, maize and milk value chains. Also, creation of awareness on aflatoxin management through training of farmers and other stakeholders and enforcement of regular surveillance of aflatoxin in food and feed chains are recommended strategies. This literature review addresses the current situation of aflatoxin occurrence in maize, dairy feeds and milk produced and traded in Kenya and current technologies applied to aflatoxin management at the farm level. Finally, a case study in Kenya on successful application of GAP for mitigation of aflatoxin risk at small-scale farms will be reviewed.

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13. The role of signal production and transduction in induced resistance of harvested fruits and vegetables

王斌, 毕阳

Food Qual Safet DOI: 10.1093/fqsafe/fyab011

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Postharvest diseases are the primary reason causing postharvest loss of fruits and vegetables. Although fungicides show an effective way to control postharvest diseases, the use of fungicides is gradually being restricted due to safety, environmental pollution, and resistance development in the pathogen. Induced resistance is a new strategy to control postharvest diseases by eliciting immune activity in fruits and vegetables with exogenous physical, chemical, and biological elicitors. After being stimulated by elicitors, fruits and vegetables respond immediately against pathogens. This process is actually a continuous signal transduction, including the generation, transduction, and interaction of signal molecules. Each step of response can lead to corresponding physiological functions, and ultimately induce disease resistance by upregulating the expression of disease resistance genes and activating a variety of metabolic pathways. Signal molecules not only mediate defense response alone, but also interact with other signal transduction pathways to regulate the disease resistance response. Among various signal molecules, the second messenger (reactive oxygen species, nitric oxide, calcium ions) and plant hormones (salicylic acid, jasmonic acid, ethylene, and abscisic acid) play an important role in induced resistance. This article summarizes and reviews the research progress of induced resistance in recent years, and expounds the role of the above-mentioned signal molecules in induced resistance of harvested fruits and vegetables, and prospects for future research.

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14. Food emulsifier glycerin monostearate aggravates phthalates’ testicular toxicity by disrupting tight junctions’ barrier function in rats

夏玲姿, 杨敏, 贺淼, 姜明哲, 秦畅, 魏智俊, 高海涛

Food Qual Safet 2021, 5 (1): 1-9. DOI: 10.1093/fqsafe/fyab002

摘要

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Objectives

This study aimed to investigate the effect of the widely used food emulsifier glycerin monostearate (GM) on testicular toxicity caused by the mixture of three commonly used phthalate esters (MPEs) in rats, and further to explore the underlying mechanism.

Materials and Methods

Thirty male Sprague–Dawley rats were randomly divided into three groups. Rats were orally treated with 160 mg/kg/d MPEs in the MPEs group; coinstantaneously treated with 160 mg/kg/d MPEs and 200 mg/kg/d GM in the MPEs?+?GM group; and treated with the excipient in the control group. The intervention lasted for 5 weeks. Testis weight, epididymis weight, testicular histopathology, and serum testosterone were detected for testicular toxicity evaluation. The testicular ultrastructure, the tight junction proteins zonula occluden (ZO)-1, and claudin were measured for the mechanism exploration.

Results

The body weight, epididymis, serum testosterone level, and anogenital distance in the MPEs?+?GM group were significantly decreased compared with control group (P?<?0.05); Testicular histopathological observation showed that shed spermatids were observed in the MPEs?+?GM group. Ultrastructural observation of testicular cells showed that the cristae number was decreased in some mitochondria in the MPEs group, whereas the cristae were fused and disappeared in most mitochondria in the MPEs?+?GM group. The tight junctions were broken in the MPEs?+?GM group; meanwhile, the expression of ZO-1 and claudin were altered in the MPEs?+?GM group (P?<?0.01).

Conclusions

The results from this study indicated that GM aggravated MPEs’ testicular toxicity, which might relate to the injured mitochondria and damaged tight junctions in testicular tissue.

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15. Developing an authentication approach using SPME-GC-IRMS based on compound-specific δ?13C analysis of six typical volatiles in wine

金新宇, 张立敏, 吴时敏, 黄明泉, 喻文娟, 张珊珊

Food Qual Safet 2021, 5 (1): 1-11. DOI: 10.1093/fqsafe/fyaa031

摘要

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An analytical method using gas chromatography isotope ratio mass spectrometry (GC-IRMS) combined with solid phase micro-extraction (SPME) was developed to measure the δ?13C values of six typical volatiles commonly occurring in wine (isoamyl acetate, 2-octanone, limonene, 2-phenylethanol, ethyl octanoate and ethyl decanoate) for the first time. SPME selected with a divinylbenzene/carboxen/polydimethylsiloxane fiber was combined with the GC-IRMS for pretreatment optimization. The optimized SPME parameters of extraction time, extraction temperature and salt concentration were 40 min, 40 °C and 10%, respectively. The δ?13C values measured by SPME-GC-IRMS were in good agreement with those measured via elemental analyzer (EA)-IRMS and GC-IRMS. The differences range from 0.02 to 0.44‰ with EA-IRMS and from 0 to 0.28‰ with GC-IRMS, indicating the high accuracy of the method. This newly established method measured the precision within 0.30‰ and was successfully validated to discriminate imported real wine samples with identical label but amazing price differences from different importers.

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16. Cumulative damage by nonthermal plasma (NTP) exceeds the defense barrier of multiple antibiotic-resistant Staphylococcus aureus: a key to achieve complete inactivation

廖新浴, Fereidoun Forghani, 刘东红, 丁甜

Food Qual Safet 2021, 5 (1): 1-14. DOI: 10.1093/fqsafe/fyaa041

摘要

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Objectives

The aim of this study was to provide a comprehensive understanding of the nonthermal plasma (NTP)-induced inactivated behaviors on a multiple antibiotic–resistant (MAR) Staphylococcus aureus (S. aureus).

Materials and Methods

A dielectric barrier discharge (DBD) NTP system was employed for the inactivation of a MAR S. aureus under various applied powers of 35, 45, and 55 W, and gas distances of 4, 6, and 8 mm. The inactivation kinetics of S. aureus were estimated with linear and nonlinear predictive models. In addition, degradation of carotenoid pigment, peroxidation of fatty acids, oxidation of nucleic acids and proteins, and alteration in gene expression were analyzed after NTP treatment.

Results and Discussion

The computationally simulated results indicated that the densities of various reactive species increased with enhanced applied powers and decreased discharge distances. These species were further transformed into reactive oxidative and nitrogen species in the gas–liquid interphase and liquid phase. The oxidative and nitrosative stress of NTP resulted in severe damage to cellular components and the morphological structure of S. aureus. On the other hand, the plasma reactive species could also induce the sublethal injury of S. aureus through upregulating the general stress response, antioxidative and antinitrosative defensive systems. Once the cumulative damages overrode the stress tolerance of S. aureus, the completed cell death was finally achieved by NTP.

Conclusions

This work infers the possible risk of inducing the repair and resistant capacity of pathogens when the applied NTP parameters are inappropriate, which helps the optimization of NTP process to achieve sufficient inactivation.

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17. Melatonin in plants: what we know and what we don’t

张子昕, 张阳

Food Qual Safet DOI: 10.1093/fqsafe/fyab009

摘要

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Melatonin is an endogenous micromolecular compound of indoleamine with multiple physiological functions in various organisms. In plants, melatonin is involved in growth and development, as well as in responses to biotic and abiotic stresses. Furthermore, melatonin functions in phytohormone-mediated signal transduction pathways. There are multiple melatonin biosynthesis pathways, and the melatonin content in plants is greatly affected by intrinsic genetic characteristics and external environmental factors. Although melatonin biosynthesis has been extensively studied in model plants, it remains uncharacterized in most plants. This article focuses on current knowledge on the biosynthesis, regulation and application of melatonin, particularly for fruit quality and preservation. In addition, it highlights the links between melatonin and other hormones, as well as future research directions.

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18. Effect of raspberry extract on wound healing

陆文静, 徐萌, 袁友卫, 张雪梅, 檀建新, 何俊萍, 田益玲

Food Qual Safet DOI: 10.1093/fqsafe/fyab013

摘要

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The main purpose of this study was to investigate the effect of raspberry extract on wound healing and compare it with that of ellagic acid. The elimination of excess free radicals was the key to preventing wound inflammation; cellular antioxidation activity was evaluated using an oxidative stress damage cell model. Cell proliferation ability was measured using the WST-1 assay, and the migration capacity was determined using the wound scratch assay. A mouse wound model was used to verify the effect of raspberry extract on wound healing. The cellular antioxidant activity of the extract ((50.31±3.17) μg/mL) was slightly lower than that of ellagic acid ((44.59±2.38) μg/mL). The results of a cell proliferation assay showed that both raspberry extract and ellagic acid at 5 μg/mL could significantly (P<0.01) promote the proliferation of HaCaT cells. After culturing for 24 h and 48 h, the cell healing rates of the extract were (41.11±0.38) per cent and (68.88±2.51) per cent, respectively, whereas the corresponding rates of ellagic acid were (39.01±2.40) per cent and (70.33±0.89) per cent; hence, there were no significant differences between them (P>0.05). The wound areas of mice fed low, medium, and high doses of raspberry extract for 14 days were 1.66, 1.41, and 1.24 mm2, respectively, which were significantly lower than that of the blank control group, 2.18 mm2 (P<0.05). These findings indicate that raspberry extract and ellagic acid exhibit similar antioxidant capacities and equivalent cell proliferation-promoting capabilities. In the mouse test, raspberry extract effectively promoted a reduction in wound area. This work demonstrates the potential of raspberry extract in wound healing, suggesting a promising application of raspberry resources in the fields of functional foods, cosmetics, and medicine.

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19. Coffee cell walls—composition, influence on cup quality and opportunities for coffee improvements

李争, 张春堂, 张媛, 曾为, Igor Cesarino

Food Qual Safet 2021, 5 (1): 1-21.

摘要

The coffee beverage is the second most consumed drink worldwide after water. In coffee beans, cell wall storage polysaccharides (CWSPs) represent around 50 per cent of the seed dry mass, mainly consisting of galactomannans and arabinogalactans. These highly abundant structural components largely influence the organoleptic properties of the coffee beverage, mainly due to the complex changes they undergo during the roasting process. From a nutritional point of view, coffee CWSPs are soluble dietary fibers shown to provide numerous health benefits in reducing the risk of human diseases. Due to their influence on coffee quality and their health-promoting benefits, CWSPs have been attracting significant research attention. The importance of cell walls to the coffee industry is not restricted to beans used for beverage production, as several coffee by-products also present high concentrations of cell wall components. These by-products include cherry husks, cherry pulps, parchment skin, silver skin, and spent coffee grounds, which are currently used or have the potential to be utilized either as food ingredients or additives, or for the generation of downstream products such as enzymes, pharmaceuticals, and bioethanol. In addition to their functions during plant development, cell walls also play a role in the plant’s resistance to stresses. Here, we review several aspects of coffee cell walls, including chemical composition, biosynthesis, their function in coffee’s responses to stresses, and their influence on coffee quality. We also propose some potential cell wall–related biotechnological strategies envisaged for coffee improvements.

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20. Effect of aluminum stress on the quality of Enteromorpha prolifera based on SEM-EDX and FT-IR

周丽萍, 王晔, 娄永江, 邵海涛, 李勇勇

Food Qual Safet 2021, 5 (1): 1-7. DOI: 10.1093/fqsafe/fyaa037

摘要

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To clarify the effect of aluminum stress on the quality of Enteromorpha prolifera (E. prolifera) and to explore the mechanism of the combination of aluminum and E. prolifera, we analyzed changes in the nutrients, micromorphology, element distribution, and spectrum of E. prolifera treated with different concentrations of aluminum (0, 0.2, 2.0, and 20.0 μmol·L–1) using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FT-IR). The biomass, protein, dietary fiber, and ash contents of E. prolifera initially increased and then subsequently decreased with an increasing concentration of aluminum. Meanwhile, the total amount of amino acids decreased. Scanning the surface of E. prolifera by SEM-EDX revealed that a high concentration of aluminum damaged the cells of E. prolifera. Additionally, the content of aluminum on the surface of E. prolifera cells increased and the absorption of other elements was also affected. The FT-IR analysis showed that aluminum might combine with the functional groups at the 3408 cm–1, 2928 cm–1, and 1072 cm–1 peaks in E. prolifera and alter the characteristic of the different absorption peaks.

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21. A novel mitigator of enzymatic browning—hawthorn leaf extract and its application in the preservation of fresh-cut potatoes

乔丽萍, 王海林, 邵金升, 路来风, 田金虎, 刘霞

Food Qual Safet DOI: 10.1093/fqsafe/fyab015

摘要

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Objectives

The purpose of this study was to evaluate the antibrowning functions of hawthorn leaf extract on fresh-cut potato and its possible mechanism.

Materials and Methods

Fresh-cut potatoes were treated with different concentrations (0.01%, 0.05%, and 0.1%) of hawthorn leaf extract and preserved at 4 ℃ for 8 days. The appearance and colour of potato slices were evaluated, along with the content of the phenol, malondialdehyde (MDA), and hydrogen peroxide (H₂O₂) during cold storage. Meanwhile, the activities of polyphenol oxidase (PPO), peroxidase (POD), phenylalanine ammonia-lyase (PAL), lipoxygenase (LOX), catalase (CAT), superoxide dismutase (SOD), and the antioxidant capacity were determined. Furthermore, the composition of hawthorn leaf extract was analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS).

Results

The addition of hawthorn leaf extract effectively delayed the browning process. It not only enhanced the CAT activity and antioxidant capacity but also reduced the LOX activity and accumulation of MDA and H₂O₂. Meanwhile, the activities of PPO, POD, and PAL as well as the content of phenol were controlled. Additionally, 25 phenols, 34 flavonoids, and 5 proanthocyanidins were identified through high-performance liquid chromatography–tandem mass spectrometry (HPLC-MS/MS), including caffeic acid, quercetin and catechol.

Conclusion

Hawthorn leaf extract significantly alleviated the browning of fresh-cut potato. It could serve as a natural antibrowning alternative by stabilizing the membrane and modulating reactive oxygen species and redox reactions.

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22. Low-temperature combined with high-humidity thawing improves the water-holding capacity and biochemical properties of Portunus trituberculatus protein

凌建刚, 宣晓婷, 徐子涵, 丁甜, 林旭东, 崔燕, 刘东红

Food Qual Safet 2021, 5 (1): 1-9. DOI: 10.1093/fqsafe/fyab008

摘要

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This study compared the effects of conventional thawing methods (water immersion thawing (WIT, (25±1) °C), natural air thawing (AT, (25±1) °C, relative humidity (RH) (65±2) per cent), refrigerator thawing (RT, 4 °C, RH (80±2) per cent) and low-temperature (LT) combined with high-humidity thawing (LT, –1 °C to 1 °C (LT–1–1), 2–4 °C (LT2–4), 5–7 °C (LT5–7) and 8–10 °C (LT8–10), RH≥95 per cent) on the water-holding capacity, lipid oxidation and biochemical properties of Portunus trituberculatus (P. trituberculatus) myofibrillar protein. The results showed that WIT and AT significantly decreased the water-holding capacity while dramatically increasing lipid oxidation, protein oxidation and degeneration, resulting in serious P. trituberculatus quality deterioration. High humidity was beneficial for P. trituberculatus thawing. The thawing time of P. trituberculatus under the conditions of LT2–4 was only 39.39 per cent of that of conventional air thawing at 4 °C (RT), and the LT2–4 samples not only maintained better water-holding capacity but also had an obviously reduced degree of lipid oxidation, protein oxidation and denaturation. Thawed samples LT2–4 and LT5–7 provided better maintenance of P. trituberculatus quality than the LT–1–1 and LT8–10 samples. The best quality was exhibited after thawing at 2–4 °C. The levels of thiobarbituric acid reacting substances, carbonyl content and surface hydrophobicity observably decreased in these samples, while the total sulfhydryl contents dramatically increased compared to those of conventionally thawed samples, indicating lower lipid oxidation and protein oxidation. Moreover, the Ca2+-ATPase activity of the sample thawed at 2–4 °C (2.06 μmol Pi/mg prot/h) was markedly higher than that of samples subjected to WIT and AT. The product qualities observed after thawing at –1 °C to 1 °C, 5–7 °C and 8–10 °C under LT were comparable to that observed by RT. Considering its thawing efficiency and product quality, LT is a suitable method for the thawing of P. trituberculatus, and the ideal thawing conditions were LT at 2–4 °C.

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23. Safety assessment of condensed phosphate intake from fishery and processed marine food products in Korea with respect to gender, age, and region

Hyung Soo Kim, Dae Yong Jang, Ye Ji Koo, Eun Chul Pack, Seung Ha Lee, Dal Woong Choi

Food Qual Safet 2021, 5 (1): 1-9. DOI: 10.1093/fqsafe/fyab003

摘要

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Condensed phosphates are used as food additives, especially in marine products and meat, to improve food quality. The import and consumption of fishery and processed marine food products in Republic of Korea have reportedly increased by ~5 per cent annually. However, processed marine food products are often intentionally adulterated with excessive amounts of condensed phosphates to increase their weight. Excessive intake of condensed phosphates via consuming processed marine food products can lead to various adverse effects on human health due to anionic imbalance. Herein, we conducted a safety assessment of condensed phosphates in 14 types of fishery and processed marine food products in Korea for the first time. Subgroup analysis of various factors including gender, age, and region was also performed, and the risk level of exposure for each group was estimated. Safety assessments by age and gender indicated that infants were at the highest risk. In the regional safety assessment, Chungnam, the most inland region, showed the lowest risk. For both the general and the high-intake groups (95th percentile) in all classifications, the risk was lower (<20 per cent) than the international standard, and the phosphorus content of the 14 types of processed marine products in Korea was confirmed to be safe for human consumption.

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24. Paper-containing 1-methylcyclopropene treatment suppresses fruit decay of fresh Anxi persimmons by enhancing disease resistance

曾玲珍, 施莉丽, 林河通, 林育钊, 林毅雄, 王慧

Food Qual Safet 2021, 5 (1): 1-8. DOI: 10.1093/fqsafe/fyab007

摘要

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Objectives

The purpose of this work was to evaluate the potential application of papers containing 1-methylcyclopropene (1-MCP) postharvest treatment for suppressing fruit decay of fresh Anxi persimmons and its possible mechanism.

Materials and methods

Anxi persimmon fruit were treated with papers containing 1-MCP at the dosage of 1.35 μL/L and stored at 25?±?1 °C and 85 per cent relative humidity for 35 days. During storage, the fruit decay rate and lignin content were evaluated, and the content of total phenolics, the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), peroxidase (POD), chitinase (CHI), and β-1,3-glucanase (GLU) were determined by spectrophotometry.

Results

The 1-MCP–treated persimmons displayed a lower fruit decay rate, but higher contents of lignin and total phenolics, higher activities of PAL, PPO, POD, CHI, and GLU.

Conclusions

The treatment with 1-MCP could inhibit the fruit decay of postharvest Anxi persimmons, which might be because 1-MCP enhanced fruit disease resistance by increasing the activities of disease resistance-associated enzymes and retaining higher contents of disease resistance-related substances in postharvest fresh Anxi persimmons. These findings indicate that papers containing 1-MCP at the dosage of 1.35 μL/L have potential application in suppressing fruit decay and extending storage life of postharvest fresh Anxi persimmons.

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25. Formation mechanism of isoprene compounds degraded from carotenoids during fermentation of goji wine

耿嘉钰, 赵璐, 张惠玲

Food Qual Safet 2021, 5 (1): 1-9. DOI: 10.1093/fqsafe/fyaa033

摘要

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Fermented goji wine as a functional wine is made from yeast fermentation. To our knowledge, fermented goji wine still has a problem with insufficient characteristic aroma. Research has shown that some isoprene compounds with characteristic aromas may improve the aroma of goji wine. Therefore, the present study aimed to investigate the mechanism of isoprene compound production by carotenoid degradation during the fermentation of goji wine. It was found that C1–C6, C5–C6, C6–C7, C7–C8, C8–C9 and C9–C10 were the most easily degraded sites in carotenoids under seven different pretreatment conditions (mechanical treatment, pectinase treatment, adjustment of pH, autoclave treatment, SO₂ treatment, oxidation treatment and light treatment). Meanwhile, breaking different sites, different aroma contributions such as woody, rose, fruity and grassy aromas were found. Single-factor simulation experiments of goji wine during the fermentation showed that the metabolites in the fermentation process caused the degradation of carotenoids and most were volatile aroma compounds. These results may help improve the brewing process to enhance the aroma of goji wine.

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26. Role of the tomato fruit ripening regulator MADS-RIN in resistance to Botrytis cinerea infection

Hui Zheng, Rong Jin, Zimeng Liu, Cui Sun, Yanna Shi ...

Food Qual Safet 2021, 5 (1): 1-. DOI: 10.1093/fqsafe/fyab028

摘要

Tomato MADS-RIN (RIN) transcription factor has been shown to be a master activator regulating fruit ripening. Recent studies have revealed that in addition to activating many other cell wall genes, it also represses expression of XTH5, XTH8, and MAN4a, which are positively related to excess flesh softening and cell wall degradation, which might indicate it has a potential role in pathogen resistance of ripening fruit. In this study, both wild-type (WT) and RIN-knockout (RIN-KO) mutant tomato fruit were infected with Botrytis cinerea to investigate the function of RIN in defense against pathogen infection during ripening. The results showed that RIN-KO fruit were much more sensitive to B. cinerea infection with larger lesion sizes. Transcriptome data and qRT-PCR assay indicate genes of phenylalanine ammonialyase (PAL) and chitinase (CHI) in RIN-KO fruit were reduced and their corresponding enzyme activities were decreased. Transcripts of genes encoding pathogenesis-related proteins (PRs), including PR1a, PRSTH2, and APETALA2/Ethylene Response Factor (AP2/ERF) including ERF.A1, Pti5, Pti6, ERF.A4, were reduced in RIN-KO fruit compared to WT fruit. Moreover, in the absence of RIN the expression of genes encoding cell wall-modifying enzymes XTH5, XTH8, MAN4a has been reported to be elevated, which is potentially correlated with cell wall properties. When present, RIN represses transcription of XTH5 by activating ERF.F4, a class II (repressor class) ERF gene family member, and ERF.F5. These results support the conclusion that RIN enhances ripening-related resistance to gray mold infection by upregulating pathogen-resistance genes and defense enzyme activities as well as reducing accumulation of transcripts encoding some cell wall enzymes.

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27. Assessment of chicken breast shelf life based on bench-top and portable near-infrared spectroscopy tools coupled with chemometrics

Ilaria Lanza, Daniele Conficoni, Stefania Balzan, Marco Cullere, Luca Fasolato, Lorenzo Serva, Barbara Contiero, Angela Trocino, Giorgio Marchesini, Gerolamo Xiccato, Enrico Novelli, Severino Segato

Food Qual Safet DOI: 10.1093/fqsafe/fyaa032

摘要

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Objectives: Near-infrared (NIR) spectroscopy is a rapid technique able to assess meat quality even if its capability to determine the shelf life of chicken fresh cuts is still debated, especially for portable devices. The aim of the study was to compare bench-top and portable NIR instruments in discriminating between four chicken breast refrigeration times (RT), coupled with multivariate classifier models. Materials and Methods: Ninety-six samples were analysed by both NIR tools at 2, 6, 10 and 14 days post mortem. NIR data were subsequently submitted to partial least squares discriminant analysis (PLS-DA) and canonical discriminant analysis (CDA). The latter was preceded by double feature selection based on Boruta and Stepwise procedures. Results: PLS-DA sorted moderate separation of RT theses, while shelf life assessment was more accurate on application of Stepwise-CDA. Bench-top tool had better performance than portable one, probably because it captured more informative spectral data as shown by the variable importance in projection (VIP) and restricted pool of Stepwise-CDA predictive scores (SPS). Conclusions: NIR tools coupled with a multivariate model provide deep insight into the physicochemical processes occurring during storage. Spectroscopy showed reliable effectiveness to recognise a 7-day shelf life threshold of breasts, suitable for routine at-line application for screening of meat quality.

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28. Delphinidin-3-O-sambubioside: a novel xanthine oxidase inhibitor identified from natural anthocyanins

谢佳宏, 崔昊昕, 徐阳, 谢亮华, 陈卫

Food Qual Safet 2021, 5 (1): 1-10. DOI: 10.1093/fqsafe/fyaa038

摘要

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Objectives This study was conducted to investigate the xanthine oxidase (XO) inhibitory activities of 18 monomeric anthocyanins from berry fruits and roselle, and to illustrate the underlying mechanism of the most active anthocyanin delphinidin-3-O-sambubioside. Materials and Methods Eighteen monomeric anthocyanins were prepared and purified in our laboratory. The inhibitory properties of anthocyanins were investigated by in vitro inhibitory activity studies and fluorescence quenching studies; the inhibitory mechanism was explored through kinetic studies, fluorescence quenching studies, circular dichroism analysis and computational docking simulations. Results XO inhibitory activities of anthocyanins were related to the structures of B rings and glycosides. Among all the tested anthocyanins, delphinidin-3-O-sambubioside showed the most potent inhibitory activity with an IC₅₀ of 17.1 μM, which was comparable to the positive control allopurinol. Spectroscopic results revealed that delphinidin-3-O-sambubioside could spontaneously interact with XO and induce conformational changes. Computational docking study indicated that delphinidin-3-O-sambubioside could bind to XO with a proper orientation, stably formed π–π interactions and hydrogen bonds with key residues, thus preventing the substrate from entering the active pocket. Conclusions In brief, our study identified delphinidin-3-O-sambubioside as a potent XO inhibitor from natural anthocyanins, which is potentially applicable for prevention and treatment of hyperuricemia.

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29. A risk scoring system for seafood supply chain breaches and examination of freshwater fish imported to Australia

Michelle Williams, Marta Hernandez-Jover, Thomas Williams, Shokoofeh Shamsi

Food Qual Safet DOI: 10.1093/fqsafe/fyab004

摘要

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Legislative changes have altered the way imported edible seafood is inspected in Australia. Greater onus of responsibility has been placed on exporting countries to provide documentary evidence of adherence to internally recognized food safety standards. According to global trade agreements, any additional safety tests applied to freshwater fish imported into Australia must be justified. Therefore, the aim of this study was to develop a risk scoring method to provide justification for identifying countries as ‘Freshwater fish high risk’ and to examine the seafood they export to Australia for seafood supply chain breaches. Scoring was conducted using six predictor variables, identified in the literature as important contributors to seafood supply chain breaches, to achieve the outcome variable, Country considered ‘Freshwater fish high risk’. Sixty-seven fish fillets (9.55 kg) of the same species were examined from the third highest scoring country (Country 20) and 562 (5.6 kg) whole fish from the sixth highest scoring country (Country 22). Country 20 had supply chain breaches of 28 macroscopic yellow cysts in one fillet. Two hundred and thirteen parasites and other supply chain breaches were identified in fish from Country 22, including retained liver (91 per cent), visible mud (11 per cent), a variety of debris (16 per cent) and, depending on the commodity code, these fish were imported to Australia under full intestine (90 per cent), retained gills (89 per cent), and partial intestine (9 per cent). Three serious physical hazards were recovered from the edible portion of three ‘consumer-ready’ fish and snails of Genus Lymnaea and Indoplanorbis were recovered from gill mud also from ‘consumer-ready’ fish. The study showed variable results from the scoring system and vast differences in seafood supply chain breaches between the third and sixth highest scoring countries.

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30. Modification of screen-printed gold electrode with 1,4-dithiothreitol: application to sensitive voltammetric determination of Sudan II

Kuddusi Karaboduk

Food Qual Safet 2021, 5 (1): 1-9.

摘要

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Objectives The aim of this study is to investigate the electrochemical behavior of Sudan II (SuII) using a screen-printed gold electrode (SPGE) modified with 1,4-dithiothreitol (DTT) and to determine the amount of Sudan II by voltammetry. Materials and Methods A DTT-modified screen-printed gold electrode (DTT/SPGE) was fabricated and its application for differential pulse voltammetric (DPV) determination of SuII was reported. Fourier transform infrared spectroscopy (FT-IR), cyclic voltammetry and electrochemical impedance spectroscopy were used for the characterization of the modified electrode. The effects of instrumental and chemical parameters were optimized for the determination of SuII. The fabricated electrode was used for the analysis of SuII in fortified and real samples. High-performance liquid chromatography was preferred as a reference method for the evaluation of the obtained voltammetric results. Results The electrochemical studies and FT-IR demonstrated that the SPGE was modified with DTT. The obtained peak current at DTT/SPGE was 6.67 times higher than that recorded with SPGE. At the optimized conditions of DPV in pH = 2.5 of H2SO4, the oxidation peak current of SuII was proportional to its concentration in range: 0.001–1.500 μmol l–1 with a detection limit of 0.0002 μmol l–1 (S/N = 3). For the analysis of SuII, 101.67%–104.33% of recovery percentage was obtained. Conclusions A new electrode was successfully improved for the determination of SuII. This highly selective and sensitive electrode supplied the fast determination of SuII in ketchup, chili sauce and salsa dip sauce. In addition, voltammetric and chromatographic results are found to be consistent.

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