The Research On Superfine Powder Quality Properties Of Black Seed Coat Of Pepper And Its Application On Biscuits

Pepper is a part of genus Zanthoxylum,belonging to the Rurtaeeae family.Pepper seed is one of the by-products during condiments producing,and the seed coat is black containing natural melanin.However,it has not been reasonable use for a long time,so it is always treated as waste or burned as fuel.In this study,in order to make full use of pepper seed coat,the superfine powder,coarse powder and fine powder of the black seed coat of pepper were prepared by two kinds of grinding methods,namely superfine grinding and regular grinding.In addition,the differences of physicochemical characteristics,antioxidant activities and adsorption characteristics among the three black seed coat powder of pepper were systematically compared.Furthermore,the superfine powder of black seed coat of pepper was supplemented into biscuitto to investigate the antioxidant effect.The main results are as follows:1.Physicochemical characteristics of black seed coat powder of pepper with different particle size were studied.Results showed that compared to the conventional crushing,super micro-grinding treatment could increase contents of the basic components,decrease the particle size of pepper black seed coat powder significantly,brighten powder color obviously,decline the crystallinity indexes,reduce the filling property,disrupt the cell walls,and thus increase the relevant water and oil holding capacity significantly,while remain the main chemical constituents unchanged.2.Antioxidant activities of black seed coat powder of pepper with different particle size were evaluated.The results showed that compared with the coarse powder,the dissolved amounts of polyphenols and flavonoids of superfine powder were increased by 19.59%and 11.24%,respectively.The DPPH?,ABTS⁺?,?OH scavenging abilities and the total reduction capacity were enhanced signific antly?P<0.05?with the decreased particle size.In addition,phenol and flavonoids contents in the black seed coat powder of pepper showed significant positive correlation with the other three kinds of antioxidant capacities?P<0.05?,except for?OH scavenging ability.3.Adsorption characteristics of Pb²⁺by the black seed coat superfine powder of pepper were investigated.Results showed that compare to the coarse powder and fine powder,the black seed coat superfine powder of pepper exhibited an effective adsorbability of Pb²⁺,and the maximum adsorption quantity was 15.54 mg/g.When the initial concentration of Pb²⁺was at 10⁹0 mg/L,the adsorption equilibrium could be described by the Langmuir isotherm revealing that the biosorption of Pb²⁺by superfine powder was a monomolecular layer adsorption.The biosorption kinetics was described by the pseudosecond-order model,the adsorption rate could be affected by film diffusionand intra-particle diffusion,and the former was the rate-limiting step.When the temperature was in the range of 25⁴5°C,thermodynamic parameters including the changes of free energy??G?,enthalpy??H?and entropy??S?were less than 0,it was suggested that the adsorption process was spontaneous,exothermic process and belonging to physical adsorption.4.Antioxidant activity of biscuits supplemented with the black seed coat superfine powder of pepper was studied.The results showed that the fortified biscuit had strong antioxidant ability,the DPPH?and ABTS⁺?scavenging activity of fortified biscuit were enhanced significantly?P<0.05?with the increased amount of the black seed coat superfine powder of pepper supplementation.Furthermore,the acid value and peroxide value of biscuit were decreased during the shelf life by the addition of certain amount of the black seed coat superfine powder of pepper.In addition,biscuits with different amount of black seed coat superfine powder of pepper showed no significant different sensory quality.Therefore,3%o f supplementation amount of black seed coat superfine powder of pepper was suggested.