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BACKGROUND: The aim of this study was to investigate the influence of high‐pressure processing (HPP) on γ‐aminobutyric acid (GABA) content, glutamic acid (Glu) content, glutamate decarboxylase (GAD) activity, growth of Aspergillus fresenii, and accumulated ochratoxin A (OTA) content in coffee beans. RESULTS: The results indicated that coffee beans subjected to HPP at pressures ≥50 MPa for 5 min increased GAD activity and promoted the conversion of Glu to GABA, and showed a significantly doubling of GABA content compared with unprocessed coffee beans. Additionally, investigation of the influence of HPP on A. fresenii growth on coffee beans showed that application ≥400 MPa reduced A. fresenii concentrations to <1 log. Furthermore, during a 50‐day storage period, we observed that a processing pressure of 600 MPa completely inhibited A. fresenii growth, and on day 50 the OTA content of coffee beans subjected to processing pressures of 600 MPa was 0.0066 μg g−1, which was significantly lower than the OTA content of 0.1143 μg g−1 in the control group. CONCLUSION: This study shows that HPP treatment can simultaneously increase GABA content and inhibit the growth of A. fresenii, thereby effectively reducing the production and accumulation of OTA and maintaining the microbiological safety of coffee beans. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND The aim of this study was to investigate the microbial levels, physicochemical and antioxidant properties and polyphenol oxidase ( PPO) and peroxidase ( POD) activities as well as to conduct a sensory analysis of white grape juice treated with high-pressure processing ( HPP) and thermal pasteurization ( TP), over a period of 20 days of refrigerated storage. RESULTS HPP treatment of 600 MPa and TP significantly reduced aerobic bacteria, coliform and yeast/mold counts. At day 20 of storage, HPP-600 juice displayed no significant differences compared with fresh juice in terms of physicochemical properties such as titratable acidity, pH and soluble solids, and retained less than 50% PPO and POD activities. Although significant differences were observed in the color, antioxidant contents and antioxidant capacity of HPP-treated juice, the extent of these differences was substantially lower than that in TP-treated juice, indicating that HPP treatment can better retain the quality of grape juice. Sensory testing showed no significant difference between HPP-treated juice and fresh juice, while TP reduced the acceptance of grape juice. CONCLUSION This study shows that HPP treatment maintained the overall quality parameters of white grape juice, thus effectively extending the shelf life during refrigerated storage. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

High-pressure processing (HPP) technology is a novel, nonthermal processing technology for food. This special processing method can inactivate microorganisms and enzymes in food at room temperature using ultra-high pressures of above 100 MPa, while the original flavor and nutritional value of the food are maintained, with an extended refrigerated shelf-life of the food in distribution. In recent years, because of the rising prevalence of food allergies, many researchers have actively sought processing methods that reduce the allergenicity of food allergens. This study describes the effects of the current HPP technology on allergen activity. Our main goal was to provide an overview of the current research achievements of the application of HPP to eliminate the allergenicity of various foods, including legumes, grains, seafood, meat, dairy products, fruits, and vegetables. In addition, the processing parameters, principles, and mechanisms of HPP for allergen destruction are discussed, such as the induction of protein denaturation, the change in protein conformation, allergen removal using the high-pressure extraction technology, and the promotion of enzymatic hydrolysis to alter the sensitization of the allergens. In the future, the application of HPP technology as a pretreatment step for raw food materials may contribute to the development of food products with low or no allergenic ingredients, which then can effectively reduce the concern for consumers with allergies, reduce the risk of mistaken ingestion, and reduce the overall incidence of allergic reactions from food. [ABSTRACT FROM AUTHOR]