Recently, research has investigated how to preserve food-destroying pathogenic and spoilage organisms while keeping food chemistry basically intact. Thermal and nonthermal processing effects on fruits and vegetables influence their antioxidant capacity.
FF&VV preservation and packaging are the processes of treating and handling them to stop or slow down food spoilage, loss of quality, edibility, or nutritional value and thus allow for longer food storage. Some breaking innovations include nanotechnology, high hydrostatic pressure technology, pulse electrified fields, aseptic packaging, free oxygen scavenging, retort and vacuum packaging. There is still the need of maintaining the nutritional and organoleptic characteristic of fresh fruits in the industrial finished product; until now, industry tried to recreate those characteristics by adding colors, flavors, and vitamins, but the final result cannot be considered really satisfactory because humans can hardly recreate natural specificity.
Still, today many studies investigate the antioxidant status of fully processed fruits, vegetables, and their products trying to achieve technology optimization to minimize losses.
Thermal processing such as sous-vide (under vacuum cooking) and post-processing storage decrease the antioxidant activity and concentration of antioxidant compound groups in fruits and vegetables. However the effect is not clear-cut, with some thermal and nonthermal strategies resulting in an increase in antioxidant activity. In general, postprocessing storage at temperatures above 0°C resulted in a decrease in antioxidant levels.
- • Sous-vide processing is a promising strategy for retaining the antioxidant capacity and color of thermally processed carrot disks.
- • High hydrostatic pressure processing at ambient temperature and pressures of 400 to 600 MPa is an excellent food-processing technology, which has the potential to retain antioxidant compounds in strawberry, blackberry, tomato, and carrot puree while also ensuring the foods are effectively pasteurized.
- • Blast freezing and storage at -18°C is a good technique for preserving ascorbic and antioxidant activity in broccoli and greens but not carrots, provided the samples had been blanched prior to freezing. (Nicoli et al., 1997).
Sous-vide processing and high hydrostatic pressure processing at ambient temperature and pressures of 400-600 MPa are two promising food processing technology for retaining the antioxidant capacity and color of thermally processed FF&VV, but the main application is the production of ready-to-use convenience foods.
High-pressure processing (HPP) has emerged as a commercially viable food manufacturing tool that satisfies consumers' demand for mildly processed, convenient, freshtasting foods with minimal to no preservatives. Pressure treatment, with or without heat, inactivates pathogenic and spoilage bacteria, yeast, mold, viruses, and also spores and extends shelf life. Pressure treatment at ambient or chilled temperatures has minimal impact on product chemistry. The product quality and shelf life are often influenced more by storage conditions and packaging material barrier properties than the treatment itself. Application of pressure reduces the thermal exposure of the food during processing, thereby protecting a variety of bioactive compounds (Balasubramaniam, Martinez-Monteagudo, and Gupta, 2015).