Fac-simile Scheda Linee di Ricerca - Federalimentare

Dati pubblicati inerenti il tema di ricerca:1) Cocci E., Rocculi P., Romani S., Dalla Rosa M. (2006) Changes in nutritional properties ofminimally processed apples during storage. Postharvest Biology and Technology 39:265-271.The effects of an antioxidant dipping treatment (in aqueous solution at 1% ascorbic acid (AA) and 1% citric acidfor three minutes) and of an alternative modified atmosphere (90% N 2 O, 5% O 2 and 5% CO 2 ) packaging (MAP)on some functional properties of minimally processed apples have been investigated. In particular, AA and totalpolyphenol (TP) contents and the overall antioxidant power of the product were monitored during 8 days ofrefrigerated storage. Colour, texture and some chemical indixes bound to the ripening stage of the product(titrable acidity and soluble solids content) were also evaluated. As a consequence of the anti-browningtreatment, the AA content of dipped samples was about 20 folds higher compared to not treated ones at thebeginning of storage and remained higher until the sixth day of refrigeration. Moreover, the dipping treatmentresulted in an increase of the apple slice antioxidant activity, while MA had a negative effect on AAmaintenance. As shown by the positive correlation between AA and TP results, TP levels were higher for treatedsamples compared to those not treated for all the storage period, because of the reducing action of AA thatprevented a high TP degradation. Results of the other physico-chemical parameters investigated confirmed thesynergistic preservative effect on the colour of MA together with the dipping treatment while a structural decayof fruit tissue was evident due to the anti-browning chemical agents adopted.2) Rocculi P., Del Nobile M.A., Romani S., Baiano A., Dalla Rosa M. (2006) Use of a simplemathematical model to evaluate dipping and MAP effects on aerobic respiration ofminimally processed apples. Journal of Food Engineering 76, 334-340.A new general respiratory model based on the Michaelis–Menten type enzyme kinetics was tested to describechanges in aerobic respiration of minimally processed apple. ‘Golden Delicious’ apple slices, washed in distilledwater or dipped in an antioxidant solution (1% ascorbic acid, 1% citric acid), were packed in multilayer pouchesin passive or active modified atmosphere (respectively air and 85% N 2 O, 10% CO 2 , 5% O 2 ). During four days ofstorage at 4°C, O 2 and CO 2 concentrations in the package headspace were monitored. The proposed modelsuccessfully fitted the experimental data, adequately describing the aerobic respiration of apple slices. Resultssuggest that both dipping treatment and active modified atmosphere affect the respiratory activity of the packedproduct. In particular, dipping reduced both the initial oxygen respiration rate (for about 10 hours of storage) andthe inhibitory effect that CO 2 had on O 2 consumption of packed product. The active modified atmospheredecreased the rate of oxygen consumption compared with passive MA, in particular at the beginning of storage.3) Rocculi P., Gomez Galindo F., Mendoza F., Wadso L., Romani S., Dalla Rosa, M. Sjoholm I.(2007) Effects of the application of anti-browning substances on the metabolic activity andsugar composition of fresh-cut potatoes. Postharvest Biology and Technology 43, 151 – 157.We investigated possible physiological effects of the application of anti-browning substances on metabolicallyactive potato tissues. The use of citric acid, ascorbic acid and l-cysteine for browning prevention of fresh-cutpotatoes increased their metabolic heat production as measured by isothermal calorimetry. This effect wasparticularly high after treatment with l-cysteine, which also proved to be the most effective substance forinhibiting enzymatic browning. This increase in metabolic activity was concentration dependent and correlatedwith a decrease in the concentration of reducing sugars in the tissue, showing evidence that substances used inthe prevention of enzymatic browning may have physiological effects in the tissue. The possible implications ofthese effects for the fresh-cut industry are discussed.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it46