Δημοσιεύσεις
Δημοσιεύσεις
2015 |
Dermesonluoglu, E. K.; Katsaros, G.; Tsevdou, M.; Giannakourou, M. C.; Taoukis, P. Kinetic study of quality indices and shelf life modelling of frozen spinach under dynamic conditions of the cold chain Journal Article In: Journal of Food Engineering, vol. 148, pp. 13-23, 2015. Abstract | Links | BibTeX | Ετικέτες: Chlorophyll, Non-isothermal frozen storage, Sensory, shelf life, Spinach, Vitamin C @article{Dermesonluoglu2015, A systematic kinetic study of quality loss of frozen spinach was conducted. Vitamin C, chlorophyll (a, b and total), colour, texture and sensory attributes were measured in frozen leafy spinach. Kinetic models of the selected quality indices were developed to determine the frozen spinach quality loss and calculate product remaining shelf life. Validated kinetic models of quality loss are applied in the evaluation, control and management of frozen spinach in the cold chain. Storage experiments were conducted at isothermal (−5, −8, −12, −18 °C) and non-isothermal temperature conditions (Teff = −6.9 °C) to validate proposed shelf life models. The temperature dependence of quality loss was adequately modelled by Arrhenius type equation and activation energy values of 132, 72, 43 and 61 kJ/mol for vitamin C loss, total chlorophyll retention, texture deterioration and overall sensory scoring were calculated respectively. The shelf life at the reference temperature of −18 °C ranged from 400 to 500 days based on the different quality indices. The effects of temperature deviations were quantitatively evaluated and a realistic assessment of the frozen spinach remaining shelf life in the actual cold chain was conducted. |
2005 |
Giannakourou, M. C.; Koutsoumanis, K.; Nychas, G. J. E; Taoukis, P. S. Modelling and Reduction of Risk of Fresh Pork Products with SMAS: a TTI Based Chill Chain Management System Journal Article In: Acta Hort, vol. 674, pp. 57-62, 2005. Abstract | Links | BibTeX | Ετικέτες: FIFO, refrigerated meat, safety, shelf life, stock-rotation, time-temperature indicators @article{Giannakourou2005b, The most difficult to control segment that affects directly safety and quality of chilled meats is the actual chill chain. Application of an optimised management for chilled distribution requires continuous monitoring and control of storage conditions from production to consumption. A novel chill chain management policy, coded “Safety Monitoring and Assurance System” (SMAS) is applied, allowing to give priority to products in such a way that, compared to the First In First Out (FIFO) current approach, risk at consumption time is minimized and quality optimised. The principles of the SMAS management approach of chilled products are developed and implemented, in order to prove the benefits of this system against the traditional FIFO. The two alternative policies (FIFO and SMAS) were compared for their effect on the quality of the products in terms of remaining shelf life, as well as for the impact on the microbiological risk at the time of consumption. The simulation results showed that, applying SMAS approach leads to significant decrease of the risk of listeriosis of ground pork products, lowering, at the same time, the number of spoiled products at the time of consumption. |
2003 |
Giannakourou, M. C.; Taoukis, PS. Kinetic modelling of Vitamin C loss in frozen green vegetables at variable storage conditions Journal Article In: Food Chemistry, vol. 83, pp. 33-41, 2003. Abstract | Links | BibTeX | Ετικέτες: Arrhenius, Distribution, Frozen vegetables, shelf life @article{Giannakourou2003, A systematic kinetic study of l-ascorbic acid loss of four green vegetables was conducted in the temperature range of freezing storage. The temperature-dependence of vitamin C loss in the −3 to −20 °C range was adequately modelled by the Arrhenius equation and activation energy ranged from 98 to 112 kJ/mol for the four frozen green vegetables. The developed models were validated in fluctuating time–temperature conditions, in order to establish their applicability in the real marketing path of the commercial products. Based on the models, the nutritional level can be estimated, at any point of the freezing chain, when the full time–temperature history is available. Comparison among different green vegetables showed that the type of plant tissue significantly affects the rate of vitamin C loss. Frozen spinach was found to be the most susceptible to vitamin C degradation, peas and green beans demonstrated a moderate retention, whereas okra exhibited a substantially lower loss rate. |
2002 |
Koutsoumanis, K.; Giannakourou, M. C.; Taoukis, PS.; Nychas, G. J. E Application of shelf life decision system (SLDS) to marine cultured fish quality Journal Article In: Int. J. Food Micro, vol. 73, pp. 375-382, 2002. Abstract | Links | BibTeX | Ετικέτες: fish quality, shelf life, SLDS @article{Koutsoumanis2002, Growth of natural microflora of marine cultured, air-packed, sea bass (Dichentrachus labrax) was studied at isothermal conditions in the 0-15 degrees C range and kinetically modelled using the four-parameter Logistic equation. Sensory shelf life was correlated to pseudomonad population and sensory acceptability was correlated to a pseudomonad level, Ns, of 10(7). The variability of their initial population was quantitatively shown and a conductance-based rapid method specific to sea bass pseudomonad enumeration was established as a practical means of N0 determination, required in shelf life predictions. Kinetic models, shelf life correlations and N0 data were incorporated into the shelf life decision system (SLDS) shown to be an effective tool for marine cultured sea bass chill chain management leading to optimization of quality of the fish at consumer's end. |
Giannakourou, M. C.; Taoukis, PS. Application of a TTI-based distribution management system for quality optimisation of frozen vegetables at the consumer end Journal Article In: J.Food Sci, vol. 68, iss. 1, pp. 201-209, 2002. Abstract | Links | BibTeX | Ετικέτες: Arrhenius, chain management, frozen, shelf life, TTI (Time Temperature Integrators) @article{Giannakourou2002b, The applicability of Time Temperature Integrators (TTI) for frozen chain management was assessed. Shelf life kinetics indices of frozen green peas and white mushrooms and response kinetics of suitable enzymatic TTI were used to confirm the monitoring effectiveness of TTI, in a controlled field test with 200 products. Comparison to actual measurements of quality indices showed that TTI response provides a reliable indication of the relative quality status of the products. The potential of Least Shelf-Life First Out (LSFO) system, a TTI based management system for frozen product distribution and stock rotation, was demonstrated by Monte Carlo technique that showed consistent, acceptable quality and minimization of rejected products at the consumer end. |