Evaluation of Morphological, Qualitative, and Metabolomic Traits during Fruit Ripening in Pomegranate (Punica granatum L.)

Impact of Novel Active Layer-by-Layer Edible Coating on the Qualitative and Biochemical Traits of Minimally Processed 'Annurca Rossa del Sud' Apple Fruit

The color changes brought on by the enzymatic interactions of phenolic compounds with released endogenous polyphenol oxidase and the penetration of oxygen into the tissue has a significant impact on the commercialization of fresh-cut fruit, such as apples. This process causes a loss of quality in fresh-cut apples, resulting in browning of the fruit surface. By acting as a semipermeable barrier to gases and water vapor and thus lowering respiration, enzymatic browning, and water loss, edible coatings can provide a chance to increase the shelf life of fresh-cut produce. In this study, the effect of edible coatings composed of carboxymethylcellulose (CMC, 1%), sodium alginate (SA, 1%), citric acid (CA, 1%), and oxalic acid (OA, 0.5%) on fresh-cut 'Annurca Rossa del Sud' apple was studied. Four formulations of edible coatings, A. SA+CMC, B. SA+CMC+CA, C. SA+CMC+OA, and D. SA+CMC+CA+OA, were tested. Fresh-cut apples were dipped into different solutions and then stored at 4 °C, and physicochemical and biochemical analyses were performed at 0, 4, 8, and 12 days of storage. Results demonstrated that all four combinations improved the shelf-life of fresh-cut apple by slowing down the qualitative postharvest decay, total soluble solid, and titratable acidity. The browning index was highest in the control samples (82%), followed by CMC+SA (53%), CMC+SA+CA (32%), CMC+SA+OA (22%), and finally CMC+SA+CA+OA (7%) after 12 days of cold storage. Furthermore, coating application increased the bioactive compound content and antioxidant enzyme activities. Furthermore, the synergistic activity of SA+CMC+CA+OA reduces enzymatic browning, prolonging the postharvest life of minimally processed 'Annurca Rossa del Sud' apples.

Multi-Functional Potential of Lactic Acid Bacteria Strains and Antimicrobial Effects in Minimally Processed Pomegranate (Punica granatum L. cv Jolly Red) Arils

This study aimed to evaluate the antimicrobial activity of both cells, and cell-free supernatants (CFS) of 7 selected lactic acid bacteria (LAB) strains belonging to Limosilactobacillus fermentum (4 strains), Lacticaseibacillus paracasei (1 strain), Lacticaseibacillus rhamnosus (1 strain), and Enterococcus faecium (1 strain) species, against Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa and Staphylococcus aureus, by both the agar-well diffusion and co-culture methods. In addition, probiotic and safety traits were also detected. Great variability was detected on antimicrobial effects, whereas all tested strains were found sensitive to most of the tested antibiotics, and without any DNase, gelatinase, or hemolytic activity. Moreover, strains showed excellent survival in acidic conditions and exhibited tolerance to pepsin and bile salts. Based on the in vitro results, the CFSs of two selected L. fermentum strains were applied, in a mixed solution, as bio-preservative into minimally processed pomegranate arils, inoculated with a cocktail of L. monocytogenes and E. coli. Samples, packaged in an ordinary atmosphere, were analyzed during refrigerated storage, for up to 12 days, for physicochemical (as weight loss, texture, color, pH, total soluble solids and organic acid content) and for microbiological traits. Results revealed the effectiveness of CFS, up to 12 days, in reducing weight loss and microbial growth, without any significant effect on texture, total soluble solid content and color, found comparable to the acid citric treatment, highlighting the multi-functional potential of selected probiotic strains.

Predicting Mandarin Fruit Acceptability: From High-Field to Benchtop NMR Spectroscopy

Recent advances in nuclear magnetic resonance (NMR) have led to the development of low-field benchtop NMR systems with improved sensitivity and resolution suitable for use in research and quality-control laboratories. Compared to their high-resolution counterparts, their lower purchase and running costs make them a good alternative for routine use. In this article, we show the adaptation of a method for predicting the consumer acceptability of mandarins, originally reported using a high-field 400 MHz NMR spectrometer, to benchtop 60 MHz NMR systems. Our findings reveal that both instruments yield comparable results regarding sugar and citric acid levels, leading to the development of virtually identical predictive linear models. However, the lower cost of benchtop NMR systems would allow cultivators to implement this chemometric-based method as an additional tool for the selection of new cultivars.