Antimicrobial Treatments to Preserve Packaged Ready-to-Eat Table Grapes

Pri skladištenju svježeg stolnog grožđa pakiranog za trenutnu konzumaciju javljaju se razni problemi poput: gubitka mase, promjene boje, ubrzanog gubitka čvrstoće bobica i razvoja plijesni, što bitno utječe na smanjenje kakvoće grozdova. Stoga su u radu uspješno ispitani postupci umakanja stolnog grožđa u otopine raznih antimikrobnih spojeva prije pakiranja za trenutnu konzumaciju. Grožđe je neposredno prije pakiranja umočeno u različite koncentracije otopina sljedećih antimikrobnih spojeva: trans-2-heksenal, kalijev sorbat, eugenol, eterično ulje kore cimeta i etanol. Svi su uzorci pakirani u biaksijalno orijentirani polipropilenski film i skladišteni na (4±1) °C. Tijekom skladištenja praćeni su sljedeći parametri: sastav plinova u pakiranju, prisutnost mikroorganizama uzročnika kvarenja, pojava vidljive plijesni i senzorske značajke grožđa. Sastav je plinova bio tipičan za neklimakterično voće, pa je zaključeno da antimikrobni spojevi nisu utjecali na intenzitet disanja plodova. Tijekom skladištenja nije bitno porastao ukupni broj bakterija, no razvojem plijesni na površini bobica promijenjene su senzorske značajke grožđa, pa je dobiven proizvod neprihvatljive kakvoće. Pritom su utvrđene velike razlike između netretiranog i tretiranog grožđa. Postupak umakanja grožđa u 50 %-tni ili 20 %-tni etanol u kombinaciji sa 3 %-tnim kalijevim sorbatom bio je vrlo učinkovit u suzbijanju pojave plijesni, čime je vrijeme skladištenja grožđa produljeno za 100 %.Ready-to-eat table grapes are a product with severe shelf life problems. Mass loss, colour changes, accelerated softening and mould proliferation can greatly influence quality decay of berries. Hence, the effects of different dipping treatments on the quality of packaged ready-to-eat table grapes have been successfully assessed. Various antimicrobial compounds (trans-2-hexenal, potassium sorbate, eugenol, cinnamon bark oil and ethanol) were used at different concentrations for dipping grape berries prior to packaging. All the samples were packaged in biaxially oriented polypropylene and stored at (4±1) °C. During the storage period, headspace gas composition, spoilage microorganisms, appearance of visible moulds and sensory quality were monitored. The composition of the headspace gas was typical of a non-climacteric fruit, thus demonstrating that the antimicrobial compounds did not affect product respiration rate. For the entire storage period, the bacterial counts did not grow significantly. On the contrary, mould proliferation on the product surface affected sensory properties until provoking product unacceptability. Relevant differences were found between the dipped and undipped samples. In particular, 50 % ethanol or 20 % ethanol combined with potassium sorbate (3 %) seemed to be very effective in preventing mould proliferation, thus promoting an increase in shelf life by about 100 %

Minimally processed butternut squash shelf life

WOS: 000308384600018The effects of dipping in antimicrobial solution and efficacy of proper film and modified atmosphere packaging conditions (MAP) on the quality decay of packaged fresh-cut butternut squash were investigated. The work was divided into three subsequent experimental trials: the first two were aimed to select the optimal packaging film mass transport properties, being micro-perforated and no-perforated films been tested. In the third experimental step, the best film (i.e., no-perforated oriented polypropylene, OPP40) was used to package sliced butternut squash under passive and active MAP. Each slice of product was dipped in aqueous solution of potassium sorbate, while no dipped samples were stored as the controls. During storage at refrigerated temperature (4 +/- 1 degrees C) headspace gas concentrations, mass loss, microbiological and sensory quality were monitored. Results obtained from the preliminary pre-screening showed that micro-perforated films did not match fresh-cut butternut squash respiratory requirements. In these films a high proliferation of moulds occurred, probably due to elevated oxygen levels. Among the no-perforated films with different thickness, the OPP40 showed better performances. In the third trial samples dipped in potassium sorbate and packaged in OPP40 under active MAP recorded a shelf-life of about 22 days respect to the no-dipped samples packaged under both passive and active MAP that reached a shelf life of about 2 weeks. (c) 2012 Elsevier Ltd. All rights reserved