Development Of The Cold Pressed Pepper Seed Oil And Its Microencapsulated Products

Pepper seed is the byproduct during the process of pepper,which accounts for 30-60% of the one pepper’s dry weight and is full of nutritional value.However,most of the seeds are discarded or are sold cheaply as fodder,and this causes serious waste of resource and pollution.For this situation,it is one of the major issues that needs to be addressed imminently,how to use pepper seeds efficiently to increase their added value and to extend the industrial chain.Using Sipingtou pepper seeds as the ingredients,this paper mainly explores three points: the first is improving the extraction process of cold pressed pepper seed oil through the response surface test;the second is exploring the basic physical and chemical indicators,bioactive substances and volatile substances of the pepper seed oil in different extraction methods;and the third is about preparing the pepper seed oil microencapsulated products in a good stability and analyzing the quality.The aim is hoping it could explore a green,safe,easy-to-operate and suitable for enterprise production of oil extraction process,solve the problems of easy oxidation,easy acidity and unstable quality of the pepper seed oil,provide a theoretical basis for the further development and utilization of the pepper seed oil,and also provide technical support for the comprehensive utilization of pepper seed resources.The main achievements as followed:(1)According to the response surface improving test,the best process for pepper seed oil is determined in 5.50% moisture content of pepper seed,23 r/min rotational speed and 8 mm pore size at the outlet of the meal,and under these conditions the extraction rate of pepper seed oil was 43.96%.This achievement is resulted by extracting pepper seed oil by the cold pressed method,taking the indicator of pepper seed oil extraction rate,and basing on a single-factor test.(2)Comparing and analyzing the physical and chemical indexes,fatty acid content,total capsaicin content,vitamin E content and volatile substances of pepper seed oil which is obtained by cold pressed method,solvent method and ultrasonic cosolvent method,the results show that different extraction methods have no significant effects on the color and malondialdehyde value of pepper seed oil(P＞0.05),but have significant effects on the acid value(P＜0.05);solvent method and ultrasonic cosolvent method have no significant effects on peroxidation,iodine and anisidine values(P＞0.05).Under the cold pressed method,solvent method and ultrasonic cosolvent method,for the pepper seed oil,the polyunsaturated fatty acid content is 70.03%,70.17%,70.15%,respectively;total capsaicin content is 0.08 mg/g,0.06 mg/g,0.08mg/g respectively;vitamin E content is 12.25 mg/100 g,9.75 mg/100 g,9.35 mg/100 g,respectively.Under the cold pressed method,31 volatile substances were qualitative from the pepper seed oil,which is more than the 22 volatile substances under organic solvent leaching method and the 19 volatile substances under ultrasonic cosolvent method.The pepper seed oil extracted by cold pressed method has a stronger spicy flavor,better physical and retains the maximum amount of its active nutrients.(3)The preparation process of pepper seed oil microcapsules is optimized by using the stochastic mass mapping optimization method,and the basic physical and chemical quality and storage stability of pepper seed oil microcapsule is also investigated.There is the optimum preparation process of the pepper seed oil microcapsule: 1.20:1 wall material compound ratio,16% solid content,0.70:1 core wall ratio,2.50%emulsifier content,and the 67.85% embedding rate of pepper seed oil microcapsule.After observing the microstructure of pepper seed oil microcapsule by using scanning electron microscope,it could be seen that pepper seed oil microcapsule shows a sheet structure of different sizes with a porous structure surface,and its particle size is evenly distributed with an average particle size of 101.98 μm.After being stored by 14 days of accelerated oxidation,the peroxide value of the pepper seed oil reached 10.95 mmol/kg,which is2.13 times that of the pepper seed oil microcapsule in the same condition.A significant oxidative acidity has occurred,which indicates that microcapsule can effectively delay oil oxidation.