Polypropylene-based packaging materials for shelf-life enhancement of yellow corn (Zea mays) kernels: Effects on lutein, aflatoxin content, sensory, and nutritional profiles

Abstract

Yellow corn (Zea mays) kernels were packaged in unilamellar polypropylene (PP), bilamellar PP/PET (polyethylene terephthalate), and trilamellar PP/PET/Al (aluminium foil) composite and stored at ambient conditions (23 ± 2 °C, 80% RH) for the extension of their shelf-lives. Lutein content, aflatoxin content, sensory, physicochemical, phytochemical, and nutritional properties were adjudged. X-ray diffraction, thermogravimetric-differential thermal analyses, differential scanning calorimetry, and percentage opacity of the three packaging composites revealed that among the three combinations investigated, PP/PET/Al composite possessed highest crystallinity, thermal stability, and percentage opacity, thereby exhibiting improved barrier properties against moisture, gas, and light. These attributes led to enhanced carotenogenesis and minimal aflatoxin content, conferring highest shelf-life of 90 days to the trilamellate packaged corn kernels, compared to PP- and PP/PET-packaged samples (60 days). Sensory, physicochemical, phytochemical, and nutritional profiles were also best retained in the same compared to PP- and PP/PET-packaged and control corn grits. Practical applications Corn is one of the major cereal crops consumed worldwide. Besides its nutritive value, it is also a good source of the nutraceutical “lutein.” Therefore, to meet the demand of the food processing industries and consumers, the grains must be preserved well. The current approach of application of non-thermal preservation technology viz. “packaging” (using commercially viable, flexible packaging materials) could well preserve lutein as well as sensory attributes, phytochemical properties and nutritional constituents of the corn grits, when stored at ambient conditions (23 ± 2 °C, 80% RH).