Expiration date determination of thermally processed potato main course in retort packaging

Consumer interest in health and wellness prompted the food industry to develop alternative processing technological solutions for preserving low-acid shelf-stable foods. The aim of this study was to assess the expiration date and quality determining factors of potato main course in retort packaging. The study was conducted at the Faculty of Food Technology and the Faculty of Veterinary Medicine, Latvia University of Agriculture. Four different potato main course typeswith amaranth (66% potato, 33% amaranth, 1% spices and salt), quinoa (66% potato, 33% quinoa, 1% spices and salt), bulgur (66% potato, 33% bulgur, 1% spices and salt) and chicken fillet (49.5% chicken fillet, potato 49.5%, 1% spices and salt)were investigated. All main courses were packaged in three different packaging materials, two-layer laminated transparent polyamide/polyethylene film (PA/PE), and four-layer opaque, laminated polyethylene terephthalate / aluminium / polyamide / polypropylene (PET/ALU/PA/PP) packaging. During the 22-month storage, mesophilic aerobic and facultative anaerobic microorganisms (TPC), pH and colour L* a* b* changes in all potato main courses were tested once every month. The results demonstrated that the expiration date of potato main course in PA/PE packaging is 8 months, while the expiration date of potato main course in PET/ALU/PA/PP packaging reaches 22 months.