Maria Lucia Valeria de Chiara

Fresh-Cut Pineapple as a New Carrier of Probiotic Lactic Acid Bacteria

Due to the increasing interest for healthy foods, the feasibility of using fresh-cut fruits to vehicle probiotic microorganisms is arising scientific interest. With this aim, the survival of probiotic lactic acid bacteria, belonging to Lactobacillus plantarum and Lactobacillus fermentum species, was monitored on artificially inoculated pineapple pieces throughout storage. The main nutritional, physicochemical, and sensorial parameters of minimally processed pineapples were monitored. Finally, probiotic Lactobacillus were further investigated for their antagonistic effect against Listeria monocytogenes and Escherichia coli O157:H7 on pineapple plugs. Our results show that at eight days of storage, the concentration of L. plantarum and L. fermentum on pineapples pieces ranged between 7.3 and 6.3 log cfu g−1, respectively, without affecting the final quality of the fresh-cut pineapple. The antagonistic assays indicated that L. plantarum was able to inhibit the growth of both pathogens, while L. fermentum was effective only against L. monocytogenes. This study suggests that both L. plantarum and L. fermentum could be successfully applied during processing of fresh-cut pineapples, contributing at the same time to inducing a protective effect against relevant foodborne pathogens.

Effect of organic agronomic techniques and packaging on the quality of lamb's lettuce: Organically produced lamb's lettuce: quality and post-harvest storage

BACKGROUND This research focused on the effect of organic production systems on initial quality and postharvest performance of lambs lettuce leaves stored in air or under modified atmosphere at refrigerated temperature. Different strategies of organic soil fertility management were compared under the same environmental conditions: (i) a simplified organic production system based on organic commercial fertilizers to recover crop uptake (SB); (ii) an organic production system based on organic matter amendment mainly supplied by animal manure (AM); and (iii) an organic production system based on organic matter amendment supplied by green waste compost (AC). Fully developed lambs lettuce leaves were harvested and then packed into perforated bags (control in AIR) or in modified atmosphere packaging (MAP) and stored at 4 °C. RESULTS At harvest, the yield of lambs lettuce in the AM and AC systems was higher than that in SB. Phenol and dehydroascorbic acid accumulation was observed in the system with the lowest initial supply of organic amendment (SB). Regarding the effect of packaging, AIR conditions maintained the initial quality attributes for a longer period than MAP, which developed off-odours above the threshold of acceptability at 11 days, irrespective of the production system used. CONCLUSION In general, the initial differences among the production systems were minimal during the postharvest storage. As for the tested packaging systems, AIR successfully maintained the initial quality attributes for a longer period than the MAP.