Shelf life extension of raspberry : passive and active modified atmosphere inside master bag solutions

Consumers often appreciate small red fruits for their high sensory quality and nutritional value. Furthermore, raspberries are very perishable presenting high respiration rates and a fragile structure; they are easily spoiled by moulds and consequently have a very short shelf life, about 3-5 days. The general purpose of this study was to investigate the ability of passive and active modified atmosphere packaging in extending the shelf life of red raspberries (Rubus idaeus L., cv. Erika). In the case of passive atmosphere, red raspberries were packed inside macro-perforated polyethylene terephthalate (PET) trays inserted in a master bag, made of plastic materials with different permeability and selectivity to oxygen and carbon dioxide. In the case of active packaging, raspberries were packaged into macro-perforated PET trays; 8 of them placed into a cardboard crate, then inserted into an low density polyethylene (LDPE) master bag before sealing, carbon dioxide emitters were introduced. For each trial, the analyses were performed at different times storing the product in a cold dark chamber (51 C, 70 %RH). We performed chemical, mechanical, sensory analyses. Consumer rejection, described by means of the Weibull's equation, was correlated to chemical and physical changes in order to find an acceptability limit useful in defining the product shelf life. The use of active and passive modified atmosphere packaging resulted in a significant increase on the shelf life of raspberries. This will have a great impact on the waste reduction of this product along the distribution chain, increasing its sustainability.