Antioxidant properties phenolic content

Zhou K and Yu L. 2006. Total phenolic contents and antioxidant properties of commonly consumed vegetables grown in Colorado. LWT Food Sci Technol 39(10) 1155—1162. 

Cauliflower has a very high waste index (Kulkami et ah, 2001) and is an excellent source of protein (16.1%), cellulose (16%), and hemicellulose (8%) (Wadhwa et ah, 2006). It is considered as a rich source of dietary fiber and it possess both antioxidant and anticarcinogenic properties. Phenolic compounds and vitamin C are the major antioxidants of brassica vegetables, due to their high content and high antioxidant activity (Podsedek, 2007). Lipid-soluble antioxidants (carotenoids and vitamin E) are responsible for up to 20% of the brassica total antioxidant activity. The level of nonstarch polysaccharide (NPS) in the upper cauliflower stem is similar to that of the floret and both are rich in pectic polysaccharides, while the cauliflower lower stem is rich in NPS due mainly to cellulose and xylan deposition (Femenia et ah, 1998). 

To date, both qualitative and quantitative judgments of the individual phenolic compounds in TBV are still unsatisfactory. The phenols in TBV were first studied in terms of their overall content by colorimetric methods and GC-MS techniques by Plessi et al. (2006) and by means of colorimetry alone by Verzelloni et al. (2007). The latter showed that the overall amount of the phenolic compounds is strictly related to the antioxidant properties of TBV. Phenols take part in the polymerization reactions during the TBV aging (Tagliazucchi et al., 2008 Verzelloni et al., 2007) and probably the reactions start during the cooking of the must. 

Verzelloni, E., Tagliazucchi, D., and Conte, A. (2007). Relationship between the antioxidant properties and the phenolic and flavonoid content in traditional balsamic vinegar. Food Chem. 105,564r-571. 

Unlike the common walnut, there is virtually no information available in peer-reviewed literature about the nutritional composition and value of heartnut. The polyphenolic and lipid compositions of the heartnut and how they contribute to the total antioxidant activities have been recently reported [2,3]. This chapter provides a more comprehensive overview about this special tree nut and its potential as a healthy food for consumers and a value-added new crop for growers. Due to lack of information about heartnut, literature reviews on the nutritional composition will mainly be on the common walnut. Furthermore, we will focus our discussions on the phenolic, tocopherol, and fatty acid contents and their contribution to human health through cholesterol reduction and antioxidative properties. 

Plant foods contain a number of bioactive substances, including phenoUcs. Phenolics such as flavonoids, phenolic acids, lignans and tannins have antioxidant properties, whilst the fermentation process has been d onstrated to modify the amount of these contents. l,l-Diphenyl-2-picryldrazyl (DPPH) and 2,2 -azinobis-(3-ethylbenzothi-azoline-6-sutfonic acid) (ABTS) are tests commonly used to detennine the free radical-scavenging effectiveness of componnds in evaluating the antioxidant activity of food systems. 

Recently there has been popular interest in the beneficial effects of foods with high ORAC values. ORAC values are an assessment of the total antioxidant content of foods (including, for example, phenols and vitamins C and E) assessed as mmol TE/kg, where TE is Trolox equivalent . Trolox is a water-soluble analogue of vitamin E with potent antioxidant properties used as a reference compound for in vitro food tests. 

Ceccarelli N, Curadi M, Martelloni L, Sbrana C, Picciarelli P, Giovannetti M (2010) Mycorrhizal colonization impacts on phenolic content and antioxidant properties of artichoke leaves and flower heads two years after field transplant. Plant Soil 335 311-323... 

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