ANTIOXIDANTS IN BLACK CARROT ( Daucus carota L.) : PROCESSING STRATEGY FOR IMPROVED STABILITY AND FUNCTIONAL QUALITY
| dc.contributor.advisor | Charanjit Kaur | |
| dc.contributor.author | VISHWANATH SAKHARAM KHANDARE | |
| dc.date.accessioned | 2017-01-05T13:29:16Z | |
| dc.date.available | 2017-01-05T13:29:16Z | |
| dc.date.issued | 2008 | |
| dc.description.abstract | Anthocyanins present in fruits and vegetables have potential beneficial health effects such as reducing age-associated oxidative stress and possessing anti- inflammatory properties. In addition, they have high potential for use as natural colorant. Black carrots a grossly underutilized vegetable has high anthocyanin content and antioxidant activity. The present study evaluates processing black carrots for enhanced phytochemical content for food applications. Black carrot were found to high total phenolic and flavonoid content of 270.74 mg GAE/100g and 94.38 mg CE/100g fresh weight respectively. The anthocyanin pigment of black carrot expressed as cyanidin 3- glucoside was 2430.45 mg/kg. Total antioxidant activity as evaluated by FRAP and CUPRAC assay was 27.75 and 60.70 μmol Trolox/g respectively. Exceptionally, high content of total phenolics, anthocyanin and antioxidant activity equates them with high antioxidant fruits such as grapes and blueberries. Results strongly point that black carrots, a underutilized vegetable is a strong candidate in terms of its antioxidant composition and can be used as value added ingredient for food applications. Extraction temperatures and enzyme assisted processing (EAP) using cell wall degrading enzyme pectinase (0.2%) remarkably improved the functional quality of black carrot juice resulting in enhanced juice yield, levels of total phenols, anthocyanin and total antioxidant activity. The total antioxidant activity in black carrot juice extracted via EAP was 29.80 μmol Trolox/ml and 62.80 μmol Trolox/ml in in-vitro FRAP and CUPRAC assay respectively. Colour values of black carrot juice as expressed by CIELAB coordinates L* (lightness), a*, b*, hue angle and C*(chroma) followed a definite trend in response to enzyme assisted processing. With increasing pectinase concentration, there is a decrease in L*, b* hue and increase in a*, chroma, ΔE va lues of juice. Drying temperatures (60-80°C) significantly affected the nutraceutical composition of black carrot slices; there was significant reduction in the total polyphenolics and total antioxidant activity. Highest retention of total phenolics and flavonoids was observed at 60°C; content of 1616.16 and 131.84 mg/100g dwb. Overall 54% of total phenolics was retained after drying. Irrespective of the drying temperatures used, anthocyanins were found to be seriously degraded during drying operations. Increasing temperature (60 to 80°C), degraded anthocyanins seriously and 6% of original content was retained. Predrying treatments (PDTs) significantly improved the total flavonoid retention in dried black carrot slices. Promising results with use of n-acetyl cysteine as a PDT prior to dehydration of black carrots corroborate the effectiveness of other anti browning agents as alternatives to sulphites. The optimized value added powder (VAP) has the potential to yield high anthocyanin rich extract (205 mg/L) Black carrot anthocyanins showed remarkable high thermal stability at high temperatures (50-100°C) in contrast to grape anthocyanins. Analysis of kinetic data suggested a first-order reaction for the degradation of black carrot anthocyanins in all food systems during both heating and storage. Coloring anthocyanin juices (black grapes), non-anthocyanin containing juices (apple, white grape, pineapple, grape fruit,) and RTS (guava and lime) colored with black carrot juice enhanced juice color and stability of anthocyanins. Technological implications Black carrots with high anthocyanin content known to have health beneficial effects have high potential value for vegetable growers as well as nutraceutical and functional food market. Valorization of black carrots can benefit the agricultural and food industries by contributing valuable phytochemical constituents Use of n-acetyl cysteine offers a viable alternative pre-drying treatment prior to drying for improving the phytochemical retention in dried black carrots. This becomes all the more important since sulphitation has been recently under critical consideration with respect to allergen labelling of foodstuffs implemented by European -Member States in November 2004. For food industry looking for viable alternatives to synthetic colourants, black carrot juice and VAP (value added powder) offer novel ingredients for increasing functionality and consumer appeal of processed products | en_US |
| dc.description.sponsorship | t-8033 | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/94661 | |
| dc.sub | Horticulture | en_US |
| dc.these.type | Ph.D | |
| dc.title | ANTIOXIDANTS IN BLACK CARROT ( Daucus carota L.) : PROCESSING STRATEGY FOR IMPROVED STABILITY AND FUNCTIONAL QUALITY | en_US |
| dc.type | Thesis | en_US |