Effect of packaging materials on the bioactive compounds, antioxidant activity, and shelf life of germinated brown rice during storage

Background and Objectives: Germinated brown rice (GBR) has been proposed as a strategy to alleviate chronic disorders by delivering nutrients and biologically active substances; therefore, appropriate packaging materials and storage are necessary to preserve these bioactive phytochemicals. In this research, we investigated the bioactive compounds, antioxidant activities, and microbial load of GBR and ungerminated brown rice stored in low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) pouches for a period of 9 months. Findings: The storage of GBR samples packed in LDPE and LLDPE was evaluated in terms of changes in the moisture content (MC), water activity (a(w)), color (L* value), bioactive components, antioxidant activities, and microbial growth. The MC, a(w), and L* values of GBR increased with prolonged storage, with a slower increase observed in samples packed in LLDPE (from 9.47% to 10.94%, from 0.394% to 0.507%, and from 59.24% to 70.68%, respectively). The bioactive components, including gamma-aminobutyric acid (GABA), gamma-oryzanol, niacin, and total phenolic contents, decreased in both packaging materials, but the decrease was minimum in samples packed in LLDPE (from 48.18 to 37.72 mg/100 g, from 72.73 to 63.92 mg/100 g, from 4.14% to 3.67%, and from 87.60% to 78.69%, respectively). The antioxidant activities of GBR were preserved when packed in LLDPE pouches stored under ambient conditions. 1,1-Diphenyl-2-picrylhydrazyl increased from 83.11 to 71.85 mu mol TE/100 g and ferric-reducing antioxidant power decreased from 16.28 to 10.67 mu mol trolox equivalents (TE)/100 g, respectively, in GBR samples packed in LLDPE. The increase in free fatty acids and the total plate count was more rapid in samples packed in LDPE (0.24-0.46 mg KOH/100 g and 0.00-1.04 colony-forming unit (CFU)/g, respectively), whereas the increase was effectively delayed in samples packed in LLDPE (0.24-0.37 mg KOH/100 g and 0.00-0.71 CFU/g, respectively). Conclusion: In the present study, it is concluded that the use of LLDPE as a packaging material for GBR could significantly retain its biologically active components and delay the deterioration of its quality during storage. Significance and Novelty: Proper storage is crucial for maintaining the quality of rice from harvest to consumption, and the use of LDPE and LLDPE pouches as packaging materials for GBR presents a novel approach that has not been extensively explored. The results of the current study demonstrate that storage of GBR in LLDPE pouches proved to be a highly effective method for preserving the valuable biologically active components, highlighting the potential of this packaging material for extending the shelf life and maintaining the nutritional value of GBR.