In the context of consumers’ increasing demand for high-quality food, the development of strategies to prolong the shelf-life of these products can attract the interest of the food industry and the processed food field. Moreover, consumers’ awareness on environmental sustainability is increasing and leads to choose alternative packaging for food products. Bio-based polymeric films are eco-friendly and good alternatives of traditional plastic packaging [1].
Pumpkin is widely cultivated in Italy throughout many regions and in many temperate climate areas of the world. It has high nutritional value because it is rich in antioxidants, vitamins, minerals, fibres and is recommended in diets because of its low calories content [2]. After harvesting, pumpkins are stable for 1-3 months; after peeling they are more perishable and rapidly lose organoleptic quality for microbial spoilage, softening, moisture loss and colour changes. For this reason, pumpkin is generally processed to obtain juice, pomace, pickles, dried products in many countries worldwide [3]. Drying is a suitable technique for preserving nutritional value and prolonging the shelf life of pumpkin. Moreover drying combined with a pretreatment is a efficient method for reducing changes in colour and antioxidant activity and for improving preservation [4].
In this study the shelf life of dried pumpkin slabs, Cocurbita moschata, packed in a polyethylene bag and in a biopolymeric bag in PLA, polylactic acid polymer from corn starch, was investigated. The objective was to evaluate the efficiency of the bio-packaging for the preservation of dried pumpkin compared to the plastic packaging (PE). The shelf life of dried foods, when properly stored, lasts from 4 to 12 months. Accelerated Shelf-life Test (ASLT) was performed in order to determine the shelf life in a relatively shorter time. By this method, the product is stored under high stress conditions, such as high temperature, to accelerate the deterioration process.
During the trial, the total microbial aerobic count, weight loss, pH and colour of the packed dried pumpkin have been monitored at 30°C every 3 days for 12 days, at 40 °C every 3 days for 9 days at 50 °C and 25°C every 2 days for 6 days. In particular the colour was expressed in terms of polar coordinate Chroma that indicates the dullness/vividness of the product.
The results obtained showed that the shelf life of dried pumpkin, packed in PLA and PE bags, can be predicted using the ASLT by selecting an index of quality
