Changes in biochemical and nutritional qualities of aerobic and vacuum-packaged Thua Nao during shelf-life storage.
Thai traditionally fermented soybean (Thua Nao) has been suggested as a good source of available amino acids and aglycone isoflavones. The objective of this research was to investigate the changes of biochemical and nutritional qualities in aerobic- and vacuum-packed thua Nao during the storage at 4 and 40 degrees C for 60 days. Three Thua Nao samples including Bacillus subtilis TN51-fermented Thua Nao (TNB51), spontaneously fermented Thua Nao (TNMX) and commercial product (MH) were used in this study. It was found that the storage of packed Thua Nao at 4 degrees C could prolong the product shelf-life up to 40 days. The moisture contents, pH values and colour L a* b* of these products were not different in both aerobic and vacuum-packaged products and remained stable throughout the experiment. The Thiobarbituric Acid (TBA) values of all storage Thua Nao were increased during storage; this is in particular for the aerobic packages of the TNMX and TNB51 products, indicating high oxidation of lipids. There was a slight decrease in DPPH radical scavenging effect (18%) and phenolic compounds (6%) of the vacuum-packaged product when stored at 4 degrees C. In contrast, the great losses in total phenolic content (44%), inhibitory activity of DPPH radicals (83%) and total antioxidant (41%) were observed when the products were stored aerobically at 40 degrees C. A reduction in total free amino acids was also found with the highest decrease of Arg in both aerobic- (69%) and vacuum-packages (68%).
Faculty of Food and Agricultural Technology, Pibulsongkram Rajabhat University, Phitsanulok 65000, Thailand.
Katekan
K
Dajantaa
Department of Food Science and Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50200, Thailand.
Arune
A
Apishartsarangku
School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.
Ekachai
E
Chukeatirote
D000975:Antioxidants / Q000032:analysis; D001412:Bacillus subtilis / Q000302:isolation & purification / Q000378:metabolism; D003116:Color; D005285:Fermentation; D005506:Food Contamination; D005516:Food Microbiology; D018857:Food Packaging; D005519:Food Preservation; D061353:Food Storage / Q000379:methods*; D005523:Food Supply; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009753:Nutritive Value; D010636:Phenols / Q000032:analysis; D045730:Soy Foods / Q000032:analysis* / Q000382:microbiology; D013696:Temperature; D017392:Thiobarbituric Acid Reactive Substances / Q000032:analysis; D013997:Time Factors; D014618:Vacuum
D000975:Antioxidants; D010636:Phenols; D017392:Thiobarbituric Acid Reactive Substances