Matrix effects on the antimicrobial capacity of silver based nanocomposite absorbing materials

Abstract

The suitability of cellulose/silver nanocomposites to decrease the microbial loads in absorbent materials was studied during the shelf-life of minimally processed foods. Cellulose/silver nanocomposites were synthesised by means of reduction by UV/heat of silver nitrate adsorbed on fluff pulp cellulose fibres. Minimally processed fruits and meat products were packaged in trays containing commercial absorbent pads or silver loaded absorbers, and stored during 10 days at 4 °C. The synthesised antimicrobial nanocomposites were useful to control the population of spoilage-related microorganisms in absorbent pads, being particularly effective in contact with low-protein food products. In contact with silver loaded absorbers, counts of total viable microorganisms and yeasts and moulds were reduced up to 99.9% in juices from kiwi fruit and melon; in drip from poultry and beef meat, microbial loads (total viable counts, lactic acid bacteria) were constantly 90% below the controls. Consequently, silver based absorbent materials could be especially designed to improve hygienic conditions during the manipulation and storage of minimally processed fruit cuts and meat products, but matrix effects must be taken into account.