Characterization of microbial population of breba and main crops (Ficus carica) during cold storage: Influence of passive modified atmospheres (MAP) and antimicrobial extract application.

The purpose of this work was to study the changes of bacterial and fungal population of breba fruits such as 'Banane' and 'San Antonio' as well as 'Cuello Dama Negro', 'Cuello Dama Blanco' and 'San Antonio' fig cultivars stored in passive modified atmospheres (MAP) by the use of three different microperforated films (M10 with 16 holes; M30 with five holes and M50 with three holes). Moreover the effects of the application of aqueous soy polyphenolic antimicrobial extract (APE), alone or combined with MAP, were also studied for 'Cuello Dama Negro' and 'Cuello Dama Blanco' fig cultivars. Bacteria and fungi isolates were identified by PCR-RFLP of 16S rRNA and ITS regions, respectively, and subsequently sequence of the different patterns obtained. The results indicated that Pseudomonas gessardii, Pantoea agglomerans and Enterobacter asburiae were the main species of bacteria found in all the treatments studied. The fungal species identified were Aureobasidium pulullans, Cladosporium cladosporioides and Alternaria alternata, which were found in a lower percentage in fruit stored in MAP and fruits treated with antimicrobial extracts, as this treatments allowed to reduce the microbial growth of moulds and yeasts. Thus, the application of treatments such as M30, M50 or the combination of MAP with antimicrobial extract was highly effective to control fruit spoilage in fig and breba crops.

Bacterial communities of fresh goat meat packaged in modified atmosphere.

The objective of this work was to study the growth and development of fortuitous flora and food pathogens in fresh goat meat packaged under modified atmospheres containing two different concentrations of CO2. Meat samples were stored at 10 °C under two different modified-atmosphere packing (MAP) conditions: treatment A had 45% CO2 + 20% O2 + 35% N2 and treatment B had 20% CO2 + 55% O2 + 25% N2. During 14 days of storage, counts of each bacterial group and dominant species identification by 16S rRNA gene sequencing were performed to determine the microbial diversity present. The MAP condition used for treatment A was a more effective gas mixture for increasing the shelf life of fresh goat meat, significantly reducing the total number of viable bacteria and enterobacteria counts. Members of the Enterobacteriaceae family were the most common contaminants, although Hafnia alvei was dominant in treatment A and Serratia proteamaculans in treatment B. Identification studies at the species level showed that different microorganisms develop under different storage conditions, reflecting the importance of gas composition in the modified atmosphere on the bacterial community. This work provides new insights into the microbial changes of goat meat storage under different MAP conditions, which will be beneficial for the meat industry.

Antioxidant and antimicrobial activity of natural phenolic extract from defatted soybean flour by-product for stone fruit postharvest application.

BACKGROUND: Fresh fruit is highly perishable during storage and transport, so there has been growing interest in finding safe and natural antimicrobial compounds as a control tool. Phenolic compounds are secondary metabolites naturally present in vegetable material and have been associated with antimicrobial and antioxidant properties. Therefore, the aim of this study was to investigate the antioxidant capacity and potential antimicrobial effect of phenolic extract obtained from defatted soybean flour against selected pathogenic bacteria and microorganisms responsible of fruit decay. RESULTS: Analysis of phenolic composition by HPLC-MS showed the presence of a wide range of compounds, with isoflavones and phenolic acids the main polyphenols identified. Furthermore, the phenolic extract had important antioxidant activity by two different assays. Related to antimicrobial activity, in vitro experiments demonstrated that phenolic extract displayed a high activity against the main foodborne pathogens, while a moderate inhibition was found against five spoilage yeasts and Monilia laxa and a scarce effect for Penicillium glabrum, Cladosporium uredinicola and Botrytis cinerea. Interestingly these compounds considerably inhibited the mycelial growth of Monilia laxa, in both in vitro and in vivo experiments. CONCLUSION: The results of the present study revealed that defatted soybean flour is an important source of phenolic compounds with remarkable antimicrobial and antioxidant activity, suggesting the possibility of using them as natural additives in postharvest treatments to extend the shelf life of fruit.

Preservation of different fig cultivars (Ficus carica L.) under modified atmosphere packaging during cold storage.

BACKGROUND: The effect of modified atmosphere packaging (MAP) on the stability of 'Cuello Dama Blanco' (CDB), 'Cuello Dama Negro' (CDN) and 'San Antonio' (SA) figs during post-harvest cold storage was evaluated by using three different films with a diverse number of microperforations (diameter, ø = 100 µm): M10 (16 holes), M30 (five holes) and M50 (three holes). A macroperforated film was used as control (five holes, ø = 9 mm). Gas composition, weight loss, percentage disorder, microbial counts and physico-chemical parameters were monitored during cold storage for 21 days. Furthermore, sensory quality was also evaluated. RESULTS: MAP has allowed the extension of cold storage and distribution time for the three different cultivars of figs, minimising weight loss and delaying pathological disorders related to endosepsis, smut, and souring. Of the three cultivars, the M50 batch (one hole per 50 mm) showed the best efficiency in terms of physico-chemical quality and delay of post-harvest decay, although the M30 batch was also found to be suitable for delaying the post-harvest decay, especially for the CDB cultivar. CONCLUSION: MAP is a useful tool to extend the storability with optimal quality properties for CDN and SA during 21 days of cold storage and 14-17 days of cold storage for CDB.

Study of microbiological quality of controlled atmosphere packaged 'Ambrunés' sweet cherries and subsequent shelf-life.

The objectives of this study were to evaluate the effect of different controlled atmospheres, containing 3% O2+10% CO2, 5% O2+10% CO2 and 8% O2+10% CO2, on changes in microbial population of 'Ambrunés' sweet cherries throughout storage during 30days and subsequent shelf-life, as well as to identify the main genera of yeast, mould, lactic acid bacteria, Staphylococcus spp., Pseudomonas spp., Enterobacteriaceae spp., and coliforms. The results indicated that controlled atmospheres with 5% O2+10% CO2 and 8% O2+10% CO2 were highly effective to control the growth of mesophilic aerobic bacteria, psychrotrophs, Pseudomonas spp., yeasts, and moulds after 15days of storage, showing, in the case of yeasts and moulds, counts that ranged between <1 and 1.75logCFU/g. The genera of yeasts, moulds, lactic acid bacteria, Enterobacteriaceae spp., and coliforms identified were Aureobasidium spp., Penicillium spp., Leuconostoc spp., and Rahnella spp., respectively. In addition, the genera Staphylococcus spp. and Pseudomonas spp. were also identified. On the other hand, cherries of Stage 3 ripening presented the highest counts for all microbial groups.