LEMON EXTRACT AS NATURAL PRESERVATIVE IN FRUIT SALAD

In this study the feasibility of using lemon extract to preserve the microbial quality of fresh fruit salad is addressed. In particular, two different packaging strategies were tested: lemon extract directly dissolved into the fruit solution and lemon extract dissolved into a gelatin that was put at the bottom of the salad tray. The microbiological quality decay kinetic of the differently packed cut fruit, stored at 4C, was determined by monitoring spoilage microorganisms for about 20 days. Results show that the active gel in the packaged fruit salad does not seem to affect to a great extent the growth of the investigated microorganisms; on the contrary, the use of the active solution seems to be effective in inhibiting the growth of the natural spoilage microflora, preserving the microbial quality of the packaged product for a longer time.

PRACTICAL APPLICATIONS

The results obtained in this research could be advantageously used by industry as a request of consumer demand for high-quality convenience food. The present research represents a starting point to develop high safety packaging systems able to prolong the shelf life of fresh cut fruit. Encouraging results on the use of natural products to control postharvest rotting indicate that it is possible to substitute the synthetic compounds with preservatives safer for man and environment.     

Confocal microscopy study of the distribution, content and activity of mitochondria during Paracentrotus lividus development

In the present paper we applied confocal microscopy and fluorescence technologies for studying the distribution and the oxidative activity of sea urchin (Paracentrotus lividus) mitochondria during development, by in vivo incubating eggs and embryos with cell‐permeant MitoTracker probes. We calculated, by a mathematical model, the intensity values, the variations of intensity, and the variation index of incorporated fluorochromes. Data demonstrate that mitochondrial mass does not change during development, whereas mitochondrial respiration increases. In addition, starting from 16 blastomeres stage, some regions of the embryo contain organelles more active in oxygen consumption.     

EFFECT OF PROCESS VARIABLES ON THE QUALITY OF SWORDFISH FILLETS FLAVORED WITH SMOKE CONDENSATE

An alternative technique to traditional smoking of swordfish was evaluated. Fillets were dry salted and/or brine salted in 30% NaCl, and smoked by dipping in smoke condensate solution at different concentrations. Chemical (water‐phase salt, pH, total volatile basic nitrogen, lipid oxidation), microbiological (total mesophilic count and fecal coliforms count) and sensory analyses were carried out in order to establish which technique gave the best results in terms of sensory quality. The different salting techniques gave different water‐phase salt contents, which influenced the microbial growth and the production of volatile bases. The smoke condensate concentration was ineffective toward microbial growth, but it was a differentiating factor for sensory panel. The dry‐salted product smoked with 5% smoke condensate was preferred because it maintained the natural taste of fish, coupled with a pleasant flavor of smoke.