ACTIVE PACKAGING IN MASTER BAG SOLUTIONS AND SHELF LIFE EXTENSION OF RED RASPBERRIES AND STRAWBERRIES: A RELIABLE STRATEGY TO REDUCE FOOD LOSS

A rough estimation for avoidable losses in the European Union (EU) is 280 kg per capita per year, of which 13% can arise from agricultural production, 31% from product processing and 45% from households. The role of packaging in preserving fresh and processed foods is well known and documented but little research is available about the relation existing among new packaging solutions, shelf life extension and Food Loss, and waste reduction at different levels at the supply chain. Techniques as Life Cycle Assessment (LCA) have been largely used to determine the Environmental Impact of food production and processing and packaging materials. However, the assessment taking into account the food and its packaging as a whole system, and of Food Loss reduction is necessary. In fact, from a life cycle perspective, no assessment of the Environmental Impact of food packaging showed the positive benefits of reduced Food Losses in the value chain. In this PhD project, the shelf life extension of red raspberries (Rubus idaeus L.) and strawberries (Fragaria x Ananassa Duch) using active packaging solutions was investigated. The shelf life extension, critical indicators and cut-off criteria were defined as a tool to point out the time at which the lifetime ended and they were elaborated by multivariate approach. The final aim was to estimate the role of a new packaging technology in reducing the Environmental Impact along the supply chain in relation to the benefits of the Food Loss reduction derived from the actual Shelf Life Extension. For raspberries trial, three packaging solutions was studied: a) Lidded macro-perforated PET trays containing 125 g of berries, stored in air and considered as “traditional” packaging; b) lidded macro-perforated PET trays containing 125 g of berries inserted into master bags made of plastic materials with different permeabilities to gas and water vapour. This solution was referred to a passive modified packaging solution. c) macro-perforated PET trays containing 125 g of berries inserted into a master bag unit made of LDPE (OTR 4000 cm3*m-2*day-1 at 23 °C and 0 %RH). Before sealing, a defined volume of compressed dry air (moisturized by using distilled water applied onto paper towels), one oxygen scavenger, and a different number of pre-activated carbon dioxide emitters were added to the master bag. For strawberries trial three packaging solutions was studied: a) Lidded PET macro-perforated trays containing 250 g of fruits and stored in air were considered as “traditional” packaging; b) lidded PET macro-perforated trays (250 g of berries/tray) were inserted into an LDPE (OTR 4000 cm3*m-2*day-1 at 23 °C and 0 %RH) master bag. c) A different number of PET macro-perforated trays were inserted into an LDPE master bag. A central composite design (CCD) with four factors (number of CO2 emitters, number of O2 scavengers, ratio between packaging surface area and unfilled volume, storage time) at five levels was performed to optimize the active packaging solution. All the samples were stored in a cold chamber (5±1 °C; 70±5 %RH). Different physical-chemical and sensorial analyses were performed as following to identify for each packaging solution the shelf life value: Damaged berries (%), Mouldy berries (%); Weight loss (%); Colour (CIE L*, a* and b* parameters); Total solids (g/100g); Soluble solids (g/100g); pH; Titratable acidity (g citric acid/100 g); Consistency determined by single compression test (force*deformation at 60% of deformation); Volatile compounds by SPME-GC-MS technique; Sensorial global and Visual acceptability. In order to analyze the results from a multidimensional point of view, the obtained data were analyzed by Principal Component Analysis (PCA). Il ciclo di vita per ogni soluzione di imballaggio è stata valutata utilizzando il software 8.0.1 SimaPro®. The boundaries of the system was set from the berries production until the retailer storage, take into consideration also the operations to disposal of the packaging materials. The functional unit for this study was set as the day of shelf life. In the raspberries studies, the active packaging solution allowed the raspberries storage up to 11 days. This value was almost three times longer than the “traditional” packaging solution that allowed a shelf life value of 4 days. The Passive packaging solution allowed lead to a shelf life extension as 2 days in comparison to the traditional packaging. For each packaging solution have been done the assessment of the environmental impact using the LCA methodology. The “traditional” packaging solution determined the highest daily impact among the packaging solutions evaluated. The passive and active packaging solutions determined a significative reduction, in terms of environmental load, up to 55% and 70%, respectively. The extension of the lifetime of berries contribute also to reduce the food loss even if the environmental impact of packaging system (active devices and master bag) was increased. This increment was balanced from the environmental impact of food saved by using the new packaging solution. The assessment of strawberries shelf life stored in the traditional packaging systems established only 2 days as value, while in the passive packaging solution lead to a shelf life extension up to 4 days longer. The optimization of the packaging factors in the active packaging solution extended the berries storage until 12 days. The “traditional” packaging determined the highest daily impact than the other packaging solutions. The passive and active packaging solutions determined a significative reduction in environmental load respect to the “traditional” solution up to 66% and 82%, respectively. The implementation of LCA methodology with lifetime data assessed by experimental shelf life trials and multivariate analyses allowed the definition of the impact of new technologies based on active packaging, taking into account their role in shelf life extension. Although based on some assumptions, this PhD study tried to explain and measure how new packaging can affect fruits losses directly or indirectly by influencing the scenarios at different levels of the supply chain. The lack of economic and logistic information about Food Losses (and specific data on this kind of fruits) in the Italian supply and distribution chain should open to new and more useful considerations.