Antimicrobial Effect of Commercial Fermentation Product and Edible Coating On Fresh-Cut Squashes

In recent years consumer preferences towards minimally processed fresh fruits and vegetables have been continuously increasing. However, minimal processing, such as sorting, peeling, coring, shredding and slicing may increase the chance of microbial spoilage and contamination of products. Therefore, developing new approaches to extend shelf-life and maintain product safety/quality represents a major task for the fresh- cut processing industry. The objective of this study was to evaluate the potential use of commercial fermentation products as natural antimicrobials and/or edible coating for fresh-cut squashes in relation to storage temperature. The antimicrobial effects of commercial fermentation product- MicroGARD^® 730 (MG) and edible coating- NatureSeal^® (NS) added to fresh-cut squashes were assessed. 0.5% MG, 1% MG, 2.5% NS, 0.5% MG plus 2.5% NS and 1% MG plus 2.5% NS were used to treat fresh-cut squashes. Samples without treatment were served as controls. Following treatments, 240g samples were put into each of polyethylene bags and stored at 4^oC and 7^oC. Changes in the microbial loads including total aerobics, yeasts and moulds, and coliforms were determined. Microorganisms were identified using API kits. Quality parameters including O₂/CO₂ concentration, pH, soluble solids, color and conductivity were evaluated following 0, 3, 7, 9, 12 and 15 days of storage. Results showed that samples treated with MG plus NS had significantly lower microbial loads (p<0.001) at 4°C and 7°C. After 6 days of storage at 7°C, aerobic plate counts were higher than 10⁷ cfu/g in controls while they were reduced by 3-4 logs in MG plus NS treated samples. The addition of MG plus NS maintained the shelf-life of fresh-cut squashes for up to 15 days compared to 9 days for 0.5% MG treated or the control samples at 4°C. It was determined that storage temperature played an important role in maintaining quality of fresh-cut squashes. Significant (p ≤0.05) differences in microbial loads and product quality were found between 4^oC and 7^oC in all treatments. Considering overall quality and shelf life, MG combined with NS was recommended to treat fresh-cut squashes prior to storage at 4°C.