Influence of de-hulled rapeseed roasting on the physicochemical composition and oxidative state of oil

The effect of roasting time on the contents of bioactive compounds (tocopherols, phytosterols, phenolic compounds), antioxidant capacity and physicochemical properties of rapeseed oil pressed from de-hulled seeds was investigated. The de-hulled seeds were roasted at a temperature of 165 °C for 20, 40, 60, 80, and 100 min. The results of this study show that a roasting pre-treatment led to a gradual increase in canolol content (from 1.34 to 117.33 mg/100 g), total phytosterols (from 573.51 to 609.86 mg/100 g) and total carotenoids (0.82 to 2.41 mg/100 g), while only slight changes in the contents of tocopherols were noted. With the increase in roasting time a gradual increase in oxidative stability (from 4.27 to 6.85 h), and antioxidant capacity, seen mainly in the hydrophilic fraction of oil (from 0.32 to 2.30 mmol TEAC/l) was found. Although roasting resulted in the formation of primary and secondary oxidation products, the quality parameters of oils were within Codex Alimentarius limits

Prebiotics and Dietary Fibers from Food Processing By-Products

The abundance of agricultural wastes or by-products from industrial and domesti- Q1 cated food processing is the main cause of environment problems. These by-products are generally managed by disposal or even sold at a cheaper price. Disposal of these underutilized by-products are commonly done in inappropriate ways, i.e. discharge effluent into rivers or by burning in the open, which may cause air and water pollutions. Presently, scientific investigation on the benefits or functional properties of waste and by-products from industrial food processing, which produces a large amount of by-products, is necessary in the search for possible ways for their utilization (Vanesa et al., 2011). Three main groups of by-product from food processing, classified according to their main chemical compositions, are carbohydrate and dietary fibers, protein and lipids. The most common by-products are generated by the food industry, in particular the beverage, starch and flour industries. These items are classified under carbohydrate and dietary fiber groups. They are further divided into four sub-groups: monosaccharides, disaccharides, oligosaccharides and polysaccharides. Dietary fibers are a class of non-starch polysaccharides (i.e. cellulose, dextrins, chitins, pectins, β-glucans and waxes) and lignin, which are able to modulate the transit time through the gut. Thus, it provides similar beneficial effects to those of inulin-type fructans. These compounds are commonly found in many foods such as cereal, nuts etc. They are also partially susceptible to bacterial fermentation and may induce changes in bacterial populations, particularly in the numerous bifidobacteria and lactobacilli. These soluble dietary fibers have been shown to exert additional beneficial effects, for instance by improving gut barrier function in vitro and in vivo, which could be partially a consequence of their effect on the microflora composition (Laparra and Sanz, 2010)

Endogenous Phenolics in Hulls and Cotyledons of Mustard and Canola: A Comparative Study on Its Sinapates and Antioxidant Capacity

Endogenous sinapic acid (SA), sinapine (SP), sinapoyl glucose (SG) and canolol (CAN) of canola and mustard seeds are the potent antioxidants in various lipid-containing systems. The study investigated these phenolic antioxidants using different fractions of canola and mustard seeds. Phenolic compounds were extracted from whole seeds and their fractions: hulls and cotyledons, using 70% methanol by the ultrasonication method and quantified using HPLC-DAD. The major phenolics from both hulls and cotyledons extracts were SP, with small amounts of SG, and SA with a significant difference of phenolic contents between the two seed fractions. Cotyledons showed relatively high content of SP, SA, SG and total phenolics in comparison to hulls (p < 0.001). The concentration of SP in different fractions ranged from 1.15 ± 0.07 to 12.20 ± 1.16 mg/g and followed a decreasing trend- canola cotyledons > mustard cotyledons > mustard seeds > canola seeds > mustard hulls > canola hulls. UPLC-tandem Mass Spectrometry confirmed the presence of sinapates and its fragmentation in these extracts. Further, a high degree of correlation (r = 0.93) was noted between DPPH scavenging activity and total phenolic content

Value-Added Potential of Expeller-Pressed Canola Oil Refining: Characterization of Sinapic Acid Derivatives and Tocopherols from Byproducts

Valuable phenolic antioxidants are lost during oil refining, but evaluation of their occurrence in refining byproducts is lacking. Rapeseed and canola oil are both rich sources of sinapic acid derivatives and tocopherols. The retention and loss of sinapic acid derivatives and tocopherols in commercially produced expeller-pressed canola oils subjected to various refining steps and the respective byproducts were investigated. Loss of canolol (<b>3</b>) and tocopherols were observed during bleaching (84.9%) and deodorization (37.6%), respectively. Sinapic acid (<b>2</b>) (42.9 μg/g), sinapine (<b>1</b>) (199 μg/g), and canolol (344 μg/g) were found in the refining byproducts, namely, soap stock, spent bleaching clay, and wash water, for the first time. Tocopherols (3.75 mg/g) and other nonidentified phenolic compounds (2.7 mg sinapic acid equivalent/g) were found in deodistillates, a byproduct of deodorization. DPPH radical scavenging confirmed the antioxidant potential of the byproducts. This study confirms the value<b>-</b>added potential of byproducts of refining as sources of endogenous phenolics