1,721,098 research outputs found
Influence of packaging material on bread characteristics
No full textThe influence of three perforated oriented polyporpylene films on the trend of bread ageing was investigated. As bread is packaged hot (80-90°C), the hole size characteristics are determinant in assuring crust crispness without inducing its wetting. The results emphasize that bread wrapped in one of the films maintained a higher crumb softness during all the storage time
The protective effect of film metallization against oxidative deterioration and discoloration of sensitive foods
No full textThe importance of the optical properties of packaging materials is often underestimated and little attention is generally given to the shelf-life of lightsensitive food products. In this paper, the effects of the light barrier of different
metallized films in delaying chemical degradative reactions, which occur in dry lasagna made with eggs and spinach, were investigated. The array of films
evaluated in the experiment accounted for a large distribution of optical properties.
Pouches prepared from the different films were filled with dry lasagna and stored at room temperature for about 4 months under a fluorescent light source. Sensory evaluations, CIE-L*, a*, b* colour measurements and hexanal formation were evaluated during storage. The shelf-life of lasagna packed in metallized films was 2.5 times greater than the same product packed in non-metallized films. A
correlation between transmittance values of the packaging films and shelf-life reduction was obtained. Because of the fat and the pigments of lasagna and also its shape (large surface area), lasagna seems to be a good model system when studying the protective performance of packaging materials against degradative reactions that involve oxygen and are very sensitive to light exposure
Primo convegno nazionale Shelf-life degli alimenti confezionati : Milano, 11-13 giugno 2003
No full textShelf life of minimally processed potatoes : part 1. Effects of high oxygen partial pressures in combination with ascorbic and citric acids on enzymatic browning
Full text linkThe shelf life of minimally processed potatoes is limited by enzyme-catalysed browning reactions. Generally, this phenomenon is controlled by the use of chemical reagents such as ascorbic acid, citric acid, or 4-hexyl resorcinol, but it seems that "oxygen shock" treatments are also particularly effective in inhibiting enzymatic browning. The aim of this work was to study the effects of high oxygen partial pressures in combination with ascorbic and citric acid on the development of the enzymatic browning of peeled and cut potatoes ('Primura' variety) that were packaged in flexible pouches and stored at 5 degrees C for 10 days. Different treatments, chosen in according to a central composite design, were applied to the sliced potatoes. The browning development during storage was measured by a tristimulus colorimeter. Second-order polynomial models were computed for three periods of storage (3, 7 and 10 days) to relate the independent variables (oxygen partial pressure, ascorbic and citric acid concentrations) to the colour function attributes. The effectiveness of the statistical approach offered the possibility to investigate the effects of several processing conditions involved in the enzymatic browning of minimally processed potatoes, while the response surface methodology allowed the identification of the optimum range of the independent variables which prevented browning. (c) 2005 Elsevier B.V. All rights reserved
Minimally processed potatoes : part 2. Effects of high oxygen partial pressures in combination with ascorbic and citric acid on loss of some quality traits
Full text linkSliced potatoes were stored in flexible packaging under different oxygen partial pressures (10, 55 and 100 kPa) after dipping treatments
with ascorbic and citric acid at different concentrations. The levels of oxygen, ascorbic and citric acid were modulated according to a Central
Composite Design. The response surface methodology allowed an assessment of the effects of these variables and their interactions on the
respiration rate in a closed system, on the carbon dioxide accumulation rate and the volatile metabolites production inside flexible pouches.
The results showed that the respiration rate did not increase in direct linear proportion to the oxygen partial pressure and there was no
significant difference in respiration between 55 and 100 kPa, even though the respiration rate was higher at these super-atmospheric oxygen
levels than at 10 kPa. Citric acid did not affect the respiration significantly, while the respiration rate increased with the increase in ascorbic
acid concentration. However, at the highest level of ascorbic acid tested (5%), the respiration rate decreased. During storage in a high barrier
plastic pouch, a higher CO2 accumulation rate was generally observed under 55 kPa than under 10 and 100 kPa. High oxygen partial pressures
(55 and 100 kPa) did not stop the production of hexanal but they had an inhibitory effect on the anaerobic volatiles productio
Studi preliminari per l'estensione della shelf life di amaretti tipici sardi
No full textIl decadimento qualitativo degli amaretti sardi è dovuto principalmente alla perdita di umidità verso l'ambiente esterno ed alla ridistribuzione della stessa fra i vari componenti della matrice di partenza ed in particolare fra pasta interna, umida e morbida, e crosta esterna, secca e croccante; la conseguenza di tutto ciò è l'indurimento nell'arco di circa sette giorni del prodotto, causa di rifiuto dello stesso da parte del consumatore. Scopo di tale lavoro è stato pertanto quello di estendere la shelf life di questo dolce tipico intervenendo, in via preliminare, su tre fonti: ricetta, packaging ed applicazione di un coating edibil
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