influence of the freezing process on the functional rheological properties of homogenised vegetable products

Introduction Achieving effective storage, preservation, and export of vegetable products while maintaining their rheological properties and nutritional benefits remains a persistent challenge. Freezing as one of the best and most natural methods for preserving taste and nutrition, is the most common procedure to achieve this goal. It acts as a natural preservative by slowing bacterial growth and preventing spoilage and oxidation by turning residual moisture into ice without a meaningful alteration in the nutritional content. Additionally, freezing greatly reduces chemical and enzymatic activity. It impacts bioactive molecules, such as antioxidants, which play a key role in combating free radicals responsible for cell damage and ageing. Measure of antioxidant activity by standard methods for different varieties allows us to find the best situation for preservation. This is a part of a big European investigation. Method and materials: In this assay for the determining of antioxidant activity before and 3 months after freezing we have used some methods such as ABTS to evaluate the ability of antioxidants to scavenge the ABTS radical cation, Folin-Ciocalteu for determining the total phenolic content, which is related to antioxidant capacity, through a redox reaction and, DPPH assay to measure the capacity of an antioxidant to donate hydrogen atoms to neutralise the DPPH radical which are stable free radicals that change colour when exposed to antioxidants. The degree of colour change reflects the antioxidant activity. Results: Analysis of four culinary products Beetroot, Cauliflower, Parsley, and Broccoli revealed that not only the different vegetables exhibit varying levels of freeze resistance and preservation of antioxidant ability, but also different varieties of each vegetable show distinct responses. Conclusion: According to many investigations the physical state of the plant product, whether whole tissue, puree, or juice, can lead to varied trends in antioxidant activity. Additionally, depending on the form in which fruits are processed before freezing and the period of freezing, there can be different outcomes in antioxidant levels. Whole fruits may release bioactive molecules due to water crystallisation, influencing antioxidant activity, while processing fruits into puree or juice before freezing can lead to chemical and enzymatic interactions, potentially lowering antioxidant levels in the final product. keywords: Free radicals, Oxidative damage, Antioxidants, Freezing, vegetable, Bioactive molecules, culinary herbs, Polyphenols