Research On Dried And Fried Pepper Processing Suitability Of The Main Varieties Of Hot Pepper In Shi Zhu County

Hot pepper (Capsicum frutescen L.syn.C.frutescents), as a kind of healthy vegetable and medicine, has been planted for nearly 400 years in China. With high nutrition, medicinal value and particular sensory quality, hot pepper is well-accepted by people from different countries, thus becoming one of the most consumed varieties of fruits and vegetables in the world. There are a variety of hot pepper in China, however, studies on the processing suitability of different varieties and processing directions are of great shortage, so were dedicated spices for specified processing, leaving uncertainty of the selection of materials for hot pepper processing and instability of the quality of products, which seriously prevented the sustainable development and large-scale production of hot pepper industry. So it will gain important economic value and social benefits, provided that the processing suitability of a variety of fried and dried hot pepper is well studied based on the utility of abundant resources of hot pepper, the uncertainty of selection of materials of hot pepper is settled, and scientific basis of selection of materials is given to large-scale production of hot pepper.In the present work, pepper cultivated in Shizhu county (Chongqing) was investgated by combined traditional physicl-chemiacl analysis and modern instrumental analysis such as, HPLC, GC-MS and so on. Principal characterization of fresh fruit of 14 varieties include Hanguohong(A), Chaotianhong(B), Changla7hao(C), Lafeng4hao(D), Ganjiao3hao(E), Yanjiao425(F), Xaingla2hao(G), Xiangla4hao(H), Xiangla9hao(I), Chuanjiaotiaozi(J), Yuanjiao(K), Zidantou(L), Erjingtiao(M) and Hongla8hao(N) had been researched. Mean time, dry products and oil product of 14 varieties had been also researched systematically and deeply. The results show as follow:In the research of characterization of fresh pepper, the results show as follow:(1) Measured values of four character indexes, including linear measure of fruitage, weight of single fruit, shape index and ratio of seeds and skin, showed high dispersion and variation differences among different varieties.(2) Varieties of B, L, A, D, C and F had the best color of red, gloss and bright red appearance quality of goods. B had the highest content of capsaicin, reached 62.496mg/g. ANV and nutrition value of B, A, F, E, J and G were higher than others. Among flavor index, content index of dried matter of A, B and F was 19.72,19.56 and 18.44g/100g, respectively. Total soluble sugar content had a small variation difference, and species I had the highest value, reached 6.68g/100g. Capsaicin content had a large range, values of B, F, A and J were apparently higher than other varieties, and B showed the highest value, up to 6.532g/kg, its SHU value was more than 0.1 million, reached 100723, thus had the highest level of spiciness.(3) Correlation analysis on indexes of fruit shape, nutritional value and flavor quality showed that small variety with thin skin was better than its counterpart with plump skin. Color of epidermis and intensity of spiciness, both are essential qualities of hot pepper as goods for sale, were mainly determined by contents of capsaicin and capsaicinoids which is higher in variety with high content of dry matter than others. Therefore, contents of dry matter, capsaicin and capsaicinoids greatly affected production quality of hot pepper.In the research of dry products and dry-making, the results show as follow:(1) Considering based on studies on variations of main qualities such as appearance of color of dry matter, and contents of protein, vitamin C, capsaicin and capsaicinoids under different temperature, and drying rate and energy cost of drying, the experiment showed that, electric blast drying was the most suitable method for large-scale drying of hot pepper and the best temperature for drying was 60℃.(2) Different drying condition leaded to big difference between variation indexes, loses of vitamin C and total sugar were large, while protein, capsaicin and capsaicinoids were small. Product dried in the shade showed the best quality, while sun-baked one had the highest loss of indexes except content of capsaicinoids, especially losses of vitamin C and capsaicin, which were the highest of all. When treated with electric blast drying, different kinds of indexes showed larger loss with higher temperature. Losses of indexes when treated with 60℃were slightly but not significantly higher than that of 50℃and 55℃, but were significantly lower than conditions of 65℃and 70℃. Therefore,60℃is the turning point of variation qualities of dry matter under experimental conditions.(3) Effects of microbes, strong ultraviolet and high temperature leaded to low value of final drying rate of variety with high content of water under conditions such as natural drying in the shade, sun baked drying,65℃and 70℃. Varieties with high content of dry matter such as B, A, F, J and E received high value of final drying rate as well as varieties with high ratio of seed and skin, therefore, it will be an important factor for selection of varieties with high value of drying rate.In the research of oil product and oil-making, the results show as follow: (1) Hot pepper oil of varieties of B, C, D and L had relatively high degree of red color, presenting bright red appearance, while variety I presenting orange was the worst kind. UV analysis showed that, oil solution of capsaicin and obtained hot pepper oil both had the maximum absorption at 475nm wavelength, therefore, capsaicin diffused in oil solution was mainly responsible for coloration of hot pepper oil. Varieties with high content of oil or seeds had a high value of acid and POV, which can be explained by high contents of fat and fatty acids in skin and seeds of hot pepper. Contents of capsaicinoids in raw materials significantly affected spiciness of fried products, such as B, F, A and J whose capsaicinoids content were much higher than other varieties.(2) Sensory evaluation showed that, sensory qualities of hot pepper oil of varieties of B, A, F and L were better than others, had bright red color and better gloss, presenting strong feeling of aromatic and spicy. Fried varieties of F, B, A, L and J showed rosy color, rich aroma and strong sense of spicy and stimulant, remaining highlighted sensory impression. Totally speaking, oil production of hot pepper showed modest aroma, but characterized with distinct feeling of spicy and stimulant, thus greatly impressed sensory assessors.(3) 42 main components had been separated from 14 kinds of hot pepper varieties, and 36 sorts of components were qualitative, including 5 sorts of alkenes,8 vinyls,3 alcohols,3 aldehydes,5 ketones,5 esters,6 fatty acids,1 Pyrazine. Vinyls were main taste substances of dried hot pepper.(4) 52 main components were fractionated from aromatic components of hot pepper oil of 14 varieties of raw materials, and 48 of which were qualitative, including 4 sorts of alkenes,5 vinyls,3 alcohols,6 aldehydes,4 ketones,18 esters,3 fatty acids and 5 other sorts of compounds.57 main components were separated from aromatic components of fried hot pepper of 14 varieties of raw materials,52 kinds of which were determined, including 5 sorts of alkenes,4 vinyls,3 alcohols,6 aldehydes,4 ketones,21 esters,3 fatty acids and 6 others. Compounds identified by application of headspace solid-phase microextraction were similar in aromatic components of fried hot pepper and its oil, primarily being weak polar or non-polar compounds.There was a big difference of change of aromatic components between fried and un-fried hot pepper. Main flavor of dried products of hot pepper was vinyl, where varieties and contents in fried hot pepper were significantly reduced, becoming mainly esters. Because of weak aroma intensity of esters, fried products showed neither particular nor intense aroma. Varieties and contents of identified flavor of before-and after-fried products with small-shaped and potent-seeds fruits and containing high content of dry matter were better than its counterparts with low content of dry matter, big-shape and less seeds. This may not only because that, small-shaped one has high content of flavor such as total sugar, but also had some relationship with reactions and changes of flavors and functional components during processes of drying and frying. (5) Taking all quality index and sensory evaluation analysis into account, oil products of B,A,F,L,J exhibited scarlet apparent color and all of them were supposed to suit for preparation of pepper oil.