HS-SPME GC-MS characterization of volatiles in processed walnuts and their oxidative stability.

J Food Sci Technol

Department of Food Science and Engineering, College of Biological Sciences and Biotechnology, Beijing Key Laboratory of Forest Food Processing and Safety, Beijing Forestry University, No. 35, Tsinghua East Road, Haidian District, Beijing City, 100083 People's Republic of China.

Published: July 2020

Processed walnuts including hot air-dried and roasted walnuts were prepared. Volatiles in raw and processed walnuts were analyzed using head-space solid phase microextraction combined with gas chromatography and mass spectrometry. Oxidative stability of hot air-dried walnuts in different antioxidants, with or without vacuum package was studied to find a proper package for oxidation stability of hot air-dried walnuts. The results showed that there were 14 volatiles in raw walnuts, 28 in hot air-dried walnuts and 38 in roasted walnuts. The changes of oil quality indices, total phenols, malondialdehyde and free radical scavenging activities during storage at 60 °C showed that the oil oxidation increased with storage time. The addition of antioxidants and vacuum package could slow down the oxidation. Vacuum aluminum foil package (14 × 20 cm) can delay the oil oxidation and extend the shelf life to ~ 230 days of hot air-dried walnuts at 20 °C. With added antioxidant this was extended to ~ 257 days.

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Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7270386PMC
http://dx.doi.org/10.1007/s13197-020-04305-9DOI Listing

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