Study On The Quality Characteristics Of Walnut From Different Species In Northwestern Hunan

In recent years,walnut is more and more popular because of high nutrition.The walnut resources in Hunan province are rich,but there are not fine varieties selected for local chaaracteristics and to be popularized.By using the principal component analysis method,the study compared the three major differences of appearance quality,nutritive quality and oil quality of walnut and carya hunanensis in northwestern Hunan Province to select fine varieties of walnut and carya hunanensis in order to develop walnut industry on a large scale,and provide theoretical basis for the development of walnut deep-processing products and new functional food.The main research results were as follows:1?There are significant differences in appearance quality,nutritional quality and oil quality of different varieties of walnuts.The single nut weight was 6.707 g to 12.303 g.The average values of transverse diameter,longitudinal diameter and lateral diameter were respectively 32.21 mm,34.62 mm and 30.60 mm.The average height and width of suture were 3.164 mm and 4.265 mm.The shell thickness was 0.798 mm to 1.615 mm.The kernel rate was 42.28%to 69.02%.The moisture of walnut kernel accounted for 4.353%,all in line with national standards.The total sugar content of walnut kernel accounted for 2.552%to 8.651%.The fat content accounted for 40.38%to 57.94%.The protein content accounted for 13.14%to 21.90%.The average content of mineral elements,from high to low in turn is P(4.707 mg/g)>K(3.440 mg/g)>Mg(1.368 mg/g)>Ca(44.92 mg/100g)>Fe(5.678 mg/100g)>Zn(3.575 mg/100 g)>Mn(3.163 mg/100 g)>Cu(1.814 mg/100 g).Five kinds of main fatty acid,stearic acid,palmitic acid,oleic acid,linoleic acid and linolenic acid,were detected in walnut oil.The content of linoleic acid was highest,followed by oleic acid.The content of unsaturated fatty acid accounted for 90.13%to 91.78%.Linolenic acid content accounted for 5.54%to 10.38%,higher than other edible oil such as soybean oil,peanut oil.2?29 indicators of 13 varieties of walnuts were transformed into 6 principal components by principal component analysis.These 6 principal components could represent 87.077%of all the comprehensive information about the main quality of walnut as comprehensive evaluation index of the quality of walnut varieties in northwestern Hunan.Comprehensive evaluation results showed that walnuts 07,05 and 13 had better comprehensive quality,which could be considered as superior strains breeding.Walnuts 07,05 and 10 were more suitable for direct consumption as nuts.Walnuts 10,06,07 and 08 were more suitable for extraction of high nutritional value of edible oil.Walnuts 07,05 and 13 were more suitable for the extraction of protein to process into protein powder,protein milk beverages and other functional products to meet different needs of people.Combined with the correlation analysis,the results showed that shape index and suture height were the important indexes to evaluate the appearance quality of walnut.Protein and moisture were the important indexes to evaluate the nutritional quality of walnut.Stearic acid and linoleic acid were the important indexes to evaluate the quality of walnut oil.Stearic acid,shape index,protein and moisture were important indicator to evaluate the comprehensive quality of walnut.3?There are significant differences in appearance quality,nutritional quality and oil quality of different varieties of carya hunanensis.The single nut weight was 7.723 g to 9.676 g.The average values of transverse diameter,longitudinal diameter and lateral diameter were respectively 26.14 mm,28.87 mm and 26.70 mm.The diaphragm thickness was 1.445 mm to 2.212 mm.The shell thickness was 1.445 mm to 1.649 mm.The kernel rate was 14.94%to 37.15%.The moisture of carya hunanensis kernel accounted for 5.300%to 6.431%.The fat content accounted for 46.32%to 60.85%,all in line with national standards.The protein content accounted for 7.700%to 10.697%.The total sugar content of carya hunanensis kernel accounted for 8.21%to 21.07%.The average content of mineral elements,from high to low in turn is K(3.471 mg/g)>P(3.393 mg/g)>Mg(1.332 mg/g)>Ca(35.42 mg/100g)>Mn(12.509 mg/100g)>Zn(5.486 mg/100g)>Fe(5.318 mg/100g)>Cu(1.930 mg/100g).Five kinds of main fatty acid,stearic acid,palmitic acid,oleic acid,linoleic acid and linolenic acid,were detected in carya hunanensis oil.The content of oleic acid was highest,followed by linoleic acid.The content of unsaturated fatty acid accounted for 88.93%to 91.25%.Linolenic acid content accounted for 1.08%to 2.09%,higher than other edible oil such as soybean oil,peanut oil.4?28 indicators of 14 varieties of carya hunanensis were transformed into 6 principal components by principal component analysis.These 6 principal components could represent 88.926%of all the comprehensive information about the main quality of carya hunanensis as comprehensive evaluation index of the quality of carya hunanensis varieties in northwestern Hunan.Comprehensive evaluation results showed that carya hunanensis S14?S13 and S12 had better comprehensive quality,which could be considered as superior strains breeding.Carya hunanensis S14?S12 and S11 were more suitable for direct consumption as nuts.Carya hunanensis S14?S13 and S12 were more suitable for extraction of protein to process into protein powder,protein milk beverages and other functional products to meet different needs of people.Carya hunanensis S12?S14 and S09 were more suitable for extraction of high nutritional value of edible oil.Combined with the correlation analysis,the results showed that transverse diameter and kernel rate were the important indexes to evaluate the appearance quality of carya hunanensis.Total sugar,K and protein were the important indexes to evaluate the nutritional quality of carya hunanensis.Linoleic acid and stearic acid were the important indexes to evaluate the quality of carya hunanensis oil.Transverse diameter,K,linoleic acid were important indicators to evaluate the comprehensive quality of carya hunanensis.In summary,walnuts 07,05 and 13 had better comprehensive quality,which could be considered as superior strains breeding.Stearic acid,shape index,protein and moisture were important indicator to evaluate the comprehensive quality of walnut.Carya hunanensis S14?S13 and S12 had better comprehensive quality,which could be considered as superior strains breeding.Transverse diameter,K,linoleic acid were important indicators to evaluate the comprehensive quality of carya hunanensis.