Effect Of Grape Seed Extract On Lipid Oxidation And Color-protection Of Chilled Pork

The objective of this thesis was to investigate the effect of grape seed extract (GSE) onlipid oxidation and color of chilled pork through the measurement of acid value (AV), peroxidevalue (POV), thiobarbituric acid value (TBA), total volatile nitrogen (TV-N), L~*value, a~*valueand b~*value. The antioxidant activities and mechanisms of GSE were evaluated by determinationof scavenging rate of1,1-Diphenyl-2-Picryl-hydrazyl radical (DPPH·), the scavenging rate ofhydroxyl radical, reducing power, the ability of chelating metal assay and antioxidant in linoleicacid system. The main results obtained were as follows:1. GSE showed inhibitory action of POV in chilled pork. The effect was greater than that ofvitamin C, butylated hydroxytoluene (BHT) and propolis but equivalent to that of catechin,propyl gallate (PG) and tertiary butylhydroquinone (TBHQ). In terms of TBA value, GSEshowed greater effect than vitamin C and propolis, as well as catechin, PG, TBHQ and BHT.Regarding inhibitory ability of TV-N value, GSE was superior to vitamin C, propolis, BHT, PGand TBHQ, but as equal to catechin.2. GSE improved a~*values and slowed down the loss of a~*value in chilled pork. This effectwas influenced by temperature, the lower the temperature the better the stability of a~*value. Thiscolor-protection effect of GSE was enhanced by vacuum package. As GSE reduced the L~*value,the chilled pork would be dark red if excessive GSE was added. Considering the balance ofantioxidant and red color stability, GSE was recommended for pork meat was0.05%(w/w).3. GSE showed a remerkable synergistic effects with vitamin C and vitamin E in inhibitionof lipid oxidation and maintenance of stability of a~*values. The compounding effect of GSE andvitamin C was greater than GSE and vitamin E.4. GSE showed great capacity of DPPH antiradical, reducing power, iron chelated andanti-lipid oxidation but a little effect of scavenging hydroxyl radical.GSE significantiy inhibited oxidation and protected red color of chilled pork. Because ofthe strong antioxidant activity, GSE is expected to be applied in the meat industry for meat fresh.