M. Cristina Nicoli

Antioxidant Properties of Ready-to-Drink Coffee Brews

The influence of some technological variables on the changes of the antioxidant capacity of ready-to-drink coffee brews was investigated. Results showed that, depending on the roasting degree as well as on the packaging conditions adopted, redox reactions, which can take place during storage, are responsible for significant changes in the overall antioxidant capacity of the product. In particular, the redox potential of air-packaged coffee brews, obtained from light- and medium-roasted beans, showed maximum values after 2 days of storage, which corresponded to a minimum in the chain-breaking activity, while, in the case of the dark-roasted sample packaged under ordinary atmosphere, both the redox potential and the chain-breaking activity showed a maximum around 2-3 days of storage. In contrast, in the absence of oxygen, the coffee brews maintained the initial reducing properties over all the storage time, although the radical-scavenging activity values changed in a way very similar to that of the air-packaged sample. These results suggested that the changes in the antioxidant properties of the coffee brews may be attributed to a further development of the Maillard reaction during storage.

Effects of drying processing on the Maillard reaction in pasta

The effect of low, high and very high drying temperatures on the development of the Maillard reaction in pasta was studied. In particular, an investigation was carried out into the influence of the different temperatures used on the development of colour, the formation of furosine and the changes in the chain breaking activity of pasta samples having different moisture contents as well as on the adsorption and desorption isotherms. Results showed that, depending on temperature, time and moisture conditions, pasta had antioxidant or pro-oxidant properties. The increase in the antioxidant potential was always associated with an increase in brown colour, while the pro-oxidant properties were observed in the early stages of the Maillard reaction.

Shelf-life extension of fresh-like ready-to-use pear cubes

Minimally processed fruit and vegetables are generally more perishable than the original raw materials due to the injury stresses during preparation that greatly increase tissue respiration and lead to deterioration through various biochemical pathways. In this paper, the effects of low intensity blanching treatments on enzymatic and microbiological stability on the fresh-like quality of ready-to- use pear cubes has been evaluated. Blanching treatments as well as packaging were carried out both in aseptic and in non-aseptic conditions. The combination of low intensity blanching with superficial enzymatic treatments has been carried out. The results confirm that the combination of a mild heat treatment (3 min at 95 °C) under aseptic conditions is enough to enhance the stability of this minimally processed product with an acceptable reduction in the texture. The superficial treatment with lysozyme did not result in an improvement in the stability of the blanched pear cubes during storage under refrigerated conditions. # 1999 Society of Chemical Industry