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BackgroundAntioxidant capacity of milk is largely due to vitamins A, E, carotenoids, zinc, selenium, superoxide dismutase, catalase, glutathione peroxidase and enzyme systems. Cow milk has antioxidant capacity while the antioxidant capacity of buffalo milk has been studied in a limited way. The information regarding the effect of pasteurization and boiling on antioxidant capacity of cow and buffalo milk is also scared.MethodsCow and buffalo milk was exposed to two different heat treatments i.e. 65 °C for 30 min and boiling for 1 min. After heat treatments, milk samples were cooled down to 4 °C packaged in transparent 250 ml polyethylene PET bottles and stored at 4 °C for 6 days. Milk composition, total flavonoid content, total antioxidant capacity, reducing power, DPPH free radical scavenging activity, antioxidant activity in linoleic acid, vitamin C, A, E, selenium, Zinc, fatty acid profile, peroxide value and sensory characteristics were studied in raw, pasteurized and boiled cow and buffalo milk at 0, 3 and 6 days of storage period.ResultsTotal antioxidant capacity (TAC) of raw, pasteurized and boiled milk for cow (42.1, 41.3 and 40.7%) and buffalo (58.4, 57.6 and 56.5%) samples was found, respectively. Reducing power (RP) of raw cow and buffalo milk was 6.74 and 13.7 while pasteurization and boiling did not showed significant effect on RP of both cow and buffalo milk. DPPH activity of raw, pasteurized and boiled milk for cow (24.3, 23.8 and 23.6%) and buffalo (31.8, 31.5 and 30.4%) samples was noted, respectively. Storage period up to 3 days was non-significant while DPPH assay after 6 days of storage period indicated significant decline in antioxidant activity of milk samples. Antioxidant activity in linoleic acid (AALA) of buffalo and cow milk were recorded 11.7 and 17.4%, respectively. Pasteurization and boiling did not showed any impact on antioxidant capacity of cow and buffalo milk. The Loss of vitamin C in pasteurization (40 and 42%) and boiling (82 and 61%) of cow and buffalo milk was recorded, respectively. Concentration of vitamin A and E in pasteurized cow and buffalo milk was not significantly different from raw milk samples of cow and buffalo. Concentration of selenium and zinc was not influenced by the heat treatment in both cow and buffalo milk samples. After 3 days of refrigerated storage, antioxidant capacity of both cow and buffalo milk decreased. Concentrations of short-chain and medium-chain fatty acids increased in pasteurized and boiled cow and buffalo milk, while long-chain fatty acids decreased in pasteurized and boiled cow and buffalo milk, with no effect on colour and flavor score. Peroxide value of pasteurized and boiled cow and buffalo milk was not influenced by the storage up to 3 days.ConclusionsThese results suggest that buffalo milk had a higher antioxidant capacity than cow milk and pasteurized milk should be consumed within 3 days of refrigerated storage for better antioxidant perspectives.

This study investigated the effect of ethanolic sesame cake extract on oxidative stabilization of olein based butter. Fractionation of cream was performed by the dry fractionation technique at 10 °C, ethanolic sesame cake extract (SCE) was incorporated into olein butter at three different concentrations; 50, 100, 150 ppm (T1, T2, T3) and compared with a control. The total phenolic content of SCE was 1.72 (mg gallic acid equivalent g−1 dry weight). The HPLC characterization of ethanolic sesame cake revealed the presence of antioxidant substances viz. sesamol, sesamin and sesamolin in higher extents. The DPPH free radical scavenging activity of SCE was 83 % as compared to 64 and 75 % in BHA and BHT. Fractionation of milk fat at 10 °C significantly (p < 0.05) influenced the fatty acid profile of olein and stearin fractions from the parent milk fat. Concentration of oleic acid and linoleic acid in olein fraction was 29.62 and 33.46 % greater than the parent milk fat. The loss of C18:1 in 90 days stored control and T3 was 24.37 and 3.58 %, respectively, 58 % C18:2 was broken down into oxidation products over 8.55 % loss in T3. The peroxide value of control, T1, T2, BHT and T3 in the Schaal oven test was 8.59, 8.12, 5.34, 4.52 and 2.49 (mequiv O2/kg). The peroxide value and anisidine value of 3 months stored control and T3 were 1.21, 0.42 (mequiv O2/kg) and 27.25, 13.25, respectively. The concentration of conjugated dienes in T3 was substantially less than the control. The induction period of T3 was considerably higher than BHT with no difference in sensory characteristics (p > 0.05). Ethanolic SCE can be used for the long‐term preservation of olein butter, with acceptable sensory characteristics.

Mango kernel contains about 15 % good quality edible oil, that is comparable to soybean and cottonseed, which contain about 18-20 % oil. Mango kernel oil (MKO) has lower free fatty acids, carotenoid content and peroxide value, and is usually used without any processing, which is otherwise mandatory for commercial vegetable oils. Palmitic, stearic and oleic acids are the major fatty acids, triglyceride composition and fatty acid profile suggest wide range of trans free options. With 32-36 °C melting point, MKO is solid at room temperature, thus, does not require partial hydrogenation for application in foods. MKO can be used as an alternative of cocoa butter, which is used in chocolates and confectionaries. Total phenolic contents and induction period of MKO is greater than many commercial vegetable oils; thus, it can be used as an alternative of synthetic antioxidants for the preservation of fats and oils. Mangiferin, chlorogenic acid, quercetin and caffeic acid are the major phenolic compounds present in MKO. Functional properties of MKO can be further improved through fractionation, transesterification and interesterification for increased industrial applications.

Whey butter is characterized with higher concentration of unsaturated fatty acids; the autoxidation of unsaturated fatty acids limits the shelf life of whey butter. We investigated the effect of almond peel extract on oxidative stabilization of whey butter at refrigeration temperature as the butter is put at refrigeration temperature in supermarkets for sale. Whey butter was added with 100 (T1), 200 (T2), 300 (T3) and 400 (T4) ppm concentrations of ethanolic almond peel extract, compared with a control, stored at refrigeration temperature (6 ± 1C). Changes in chemical characteristics were studied at the interval of 45 days. Supplementation of whey butter with almond peel extract did not show any effect on compositional attributes, rather it strongly inhibited the peroxidation of unsaturated fatty acids (P < 0.05). The iodine value of whey butter was greater than normal butter with no difference in refractive index and unsaponifiable matter. The peroxide value of 90-day stored whey butter added with 400 ppm almond peel extract and control was 0.62 and 1.59 (meqO2/kg). Supplementation of whey butter with almond peel extract markedly improved the induction period. Sensory characteristics of supplemented whey butter were not different from the normal butter (P > 0.05). Almond peel extract can be used for the long-term preservation of whey butter at refrigeration temperature. PRACTICAL APPLICATIONSThe increased awareness of health benefits of natural antioxidant and professed of synthetic antioxidants has opened new arrays of the application of natural antioxidants. Almond peel extract can be used to improve the shelf stability of whey butter.