Theofania Tsironi

Application and validation of the TTI based chill chain management system SMAS (Safety Monitoring and Assurance System) on shelf life optimization of vacuum packed chilled tuna.

The objective of the study was to establish a validated kinetic model for growth of spoilage bacteria on vacuum packed tuna slices in the temperature range of 0 to 15 degrees C and to evaluate the applicability of the TTI (Time Temperature Integrators) based SMAS (Safety Monitoring and Assurance System) system to improve tuna product quality at the time of consumption in comparison to the conventional First In First Out (FIFO) approach. The overall measurements of total flora and lactic acid bacteria (LAB) on the tuna samples used in a laboratory simulated field test were in close agreement with the predictions of the developed kinetic model. The spoilage profile of the TTI bearing products, handled with SMAS, was improved. Three out of the thirty products that were handled randomly, according to the FIFO approach, were already spoiled at the time of consumption (logN(LAB)>6.5) compared to no spoiled products when handled with the SMAS approach.

Shelf-life prediction models for ready-to-eat fresh cut salads: Testing in real cold chain

The aim of the study was to develop and test the applicability of predictive models for shelf-life estimation of ready-to-eat (RTE) fresh cut salads in realistic distribution temperature conditions in the food supply chain. A systematic kinetic study of quality loss of RTE mixed salad (lollo rosso lettuce-40%, lollo verde lettuce-45%, rocket-15%) packed under modified atmospheres (3% O2, 10% CO2, 87% N2) was conducted. Microbial population (total viable count, Pseudomonas spp., lactic acid bacteria), vitamin C, colour and texture were the measured quality parameters. Kinetic models for these indices were developed to determine the quality loss and calculate product remaining shelf-life (SLR). Storage experiments were conducted at isothermal (2.5-15°C) and non-isothermal temperature conditions (Teff=7.8°C defined as the constant temperature that results in the same quality value as the variable temperature distribution) for validation purposes. Pseudomonas dominated spoilage, followed by browning and chemical changes. The end of shelf-life correlated with a Pseudomonas spp. level of 8 log(cfu/g), and 20% loss of the initial vitamin C content. The effect of temperature on these quality parameters was expressed by the Arrhenius equation; activation energy (Ea) value was 69.1 and 122.6kJ/mol for Pseudomonas spp. growth and vitamin C loss rates, respectively. Shelf-life prediction models were also validated in real cold chain conditions (including the stages of transport to and storage at retail distribution center, transport to and display at 7 retail stores, transport to and storage in domestic refrigerators). The quality level and SLR estimated after 2-3days of domestic storage (time of consumption) ranged between 1 and 8days at 4°C and was predicted within satisfactory statistical error by the kinetic models. Teff in the cold chain ranged between 3.7 and 8.3°C. Using the validated models, SLR of RTE fresh cut salad can be estimated at any point of the cold chain if the temperature history is known. Shelf-life models of validated applicability can serve as an effective tool for shelf-life assessment and the development of new products in the fresh produce food sector.

Food Cold Chain Management and Optimization

The main shelf life determining post-processing parameter for chilled and frozen food products is temperature. Possible temperature fluctuations and even unexpected, out of specifications, temperature conditions throughout the cold chain should be considered when developing a cold chain management and quality/safety assurance system. This chapter describes the use of two different approaches for an effective cold chain management and optimization.

Current Practice and Innovations in Fish Packaging

ABSTRACT Fish and seafood are food products of high commercial value but with short shelf life. The objective of this article is to review the available packaging techniques and their applications on fish products, focusing on research and latest innovations. Modified atmosphere packaging (MAP) has been investigated for the selection of optimum packaging conditions for different fish products. Recent innovations include the combined application of MAP with other preservative factors, such as minimal processing or the addition of antioxidant and/or antimicrobial compounds. Smart packaging, including active packaging and quality control and monitoring systems (gas and moisture control, antimicrobial/antioxidant packaging, smart labels) and edible films and coatings are innovative packaging technologies, which may result in higher quality and extended shelf life of perishable food. The market for active and intelligent packaging methods is anticipated to rise significantly in the near future with their integration into fish packaging.