Background: Vinegars based on fruit juices could conserve part of the health-associated compounds present in the fruits. However, in general very limited knowledge exists on the consequences of vinegar-making on different antioxidant compounds from fruit. In this study vinegars derived from apple and grape are studied. Methods: A number of steps, starting from the fermentation of the fruit juices to the formation of the final vinegars, were studied from an industrial vinegar process. The effect of each of the vinegar processing steps on content of antioxidants, phenolic compounds and flavonoids was studied, by spectroscopic methods and by high-performance liquid chromatography (HPLC). Results: The major observation was that spectrophotometric methods indicate a strong loss of antioxidant phenolic compounds during the transition from fruit wine to fruit vinegar. A targeted HPLC analysis indicates that metabolites such as gallic acid are lost in later stages of the vinegar process. Conclusion: The major conclusion of this work is that major changes occur in phenolic compounds during vinegar making. An untargeted metabolite analysis should be used to reveal these changes in more detail. In addition, the effect of vinegar processing on bio-accessibility of phenolic compounds was investigated by mimicking the digestive tract in an in vitro set up. This study is meant to provide insight into the potential of vinegar as a source of health-related compounds from fruit.
BACKGROUND: Excessive production of grape is valorized by traditional drying and homemade jam production in some regions of Algeria. OBJECTIVE: This study aims to investigate the changes in antioxidant activity, phenolic compounds and their bioaccessibility in two grape varieties (Cardinal and Dabouki or Sabel) as a result of traditional sun drying and homemade jam processes. METHODS: Fresh and dried grapes, as well as jam samples were subjected to a series of spectrophotometric analyses including total phenolics, flavonoids, and antioxidant activity. Individual phenolic compounds were identified and quantified by HPLC-DAD-MS-QTOF. An in vitro gastrointestinal digestion was applied to evaluate the bioaccessibility. RESULTS: Both traditional processes led to considerable losses in the levels of some phenolic compounds and their antioxidant activities. However, an increase in the content of other phenolic acids was also observed after processing. Total phenolics, total flavonoids and total antioxidant capacity recovery values of the dialysable fraction of processed samples were higher than those of fresh grapes for both varieties. CONCLUSIONS: Traditional raisins and homemade jams could be considered as good sources of natural antioxidants, although a modification of some critical steps that may negatively affect their antioxidant properties is suggested in the light of this study.
This review presents the potential effects of dietary antioxidants on neurodegenerative diseases. The relationship of autoimmunity and antioxidants, as well as their preventive effect on neurodegenerative diseases are evaluated. The driven factors of neurodegeneration and the potential effects of natural antioxidants are summarized for Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, spongiform encephalopathy, Huntington’s disease, and amyotrophic lateral sclerosis (ALS). The effect of oxidative stress on neurodegenerative diseases and regulative effect of antioxidants on oxidative balance is discussed. This review provides beneficial information for the possible cure of neurodegenerative diseases with dietary intake of antioxidants.