Nutritional Quality And Yield Of Sweetpotato Sprouts With Different Culture Conditions

Sprouts vegetables is a type of nutrition-rich,crisp taste of health-care vegetables,which is very popular with people.With the development of the agricultural supply-side structural reform in China,the innovation and cultivation techniques of sprouts varieties have been further studied and exploitated.In this paper,sensory evaluation of sweetpotato sprouts and sprouting evaluation of sweetpotato tubers were carried out on 21 different types of sweetpotato in China,and sweetpotato varieties suitable for producing sweetpotato sprouts were selected as follows:Fushu 7-6,Xushu 22 and Shangshu 19respectively.In order to screen out the optimum conditions for sweetpotato sprouts production,we selected three varieties of sweetpotato as the materials to explore the effects of li ght intensity and photoperiod on the leaf color,nutritional quality,antioxidation,texture and yield of sweetpotato sprouts.Meanwhile,the effects of different nutrient solution and tuber size on the yield and nutritional quality of sweetpotato sprouts were explored to find out the optimum nutrient solution and tuber size to provide the theoretical basis for the commercial production of sweetpotato sprouts.The main results are as follows:(1)The leaf color,nutrition composition and texture characteristics of the three varieties varies under different treatments.The L~*(brightness)value of sweetpotato sprouts was significantly and positively correlated with soluble sugar content,and it was significantly and negatively correlated with Vitamin C,crude protein and anthocyanin content and DPPH clearance rate.The soluble sugar content of sweetpotato sprouts was significantly and negatively correlated with the content of Vitamin C and crude protein(P<0.01).The DPPH clearance rate of sweetpotato sprouts was significantly and positively correlated with the content of Vitamin C,crude protein and anthocyanin The hardness of sweetpotato sprouts was significantly and negatively correlated with the content of soluble sugar,which was significantly and positively correlated with the content of Vitamin C,crude protein and DPPH,and it has a significant positive correlation with anthocyanin content(P<0.05).The soluble sugar content of sweetpotato sprouts was negatively correlated with DPPH clearance rate(P<0.05).(2)Compared with dark conditions,the the nutritional quality of three varieties of sweetpotato sprouts in different light conditions is better,and the content of crude protein and anthocyanin is higher.The nutritional qualities of three cultivation sweetpotato sprouts were similar in different light culture samples,but they were not suitable for cultivation under SL-2(2250 lux,2h/d),because it has the hightest chewiness and did not possess the tender taste of sprouts vegetables.The total yield of three cultivars of sweetpotato sprouts under WL-2(750 lux,2h/d)condition was the highest,that of Fushu7-6 sweetpotato was 136.16 g,Xushu 22 was 152.46 g,Shangshu 19 was 157.07 g.Meanwhile,the leaf color of Xushu 22 and Fushu 7-6 sweetpotato sprouts is yellow-green,while the leaf color of Shushan19 sweetpotato sprouts are orange red with good appearance of the products.In addition,under the conditions of WL-2(750 lux,2h/d),the chewing of three varieties of sweetpotato sprouts was equivalent to the chewing of dark conditions.which was in line with the characteristics of sprouts vegetables taste.Therefore,combining the leaf color,nutritional quality,antioxidant and total yield of sweetpotato sprouts,750 lux light intensity and 2 h/d photoperiod were considered to be the suitable conditions for the production of crisp,high quality and high yield sweetpotato sprouts.(3)Compared with the water treatment,three different nutrient solution treatment of sweetpotato sprouts can be harvested two days in advance.Among them,the soluble sugar content(32.83mg/100 g)and the crude protein content(12.79 mg/100g)and the DPPH clearance rate(88.95%)of the sweetpotato sprouts treated with 1/2MS nutrient solution were the highest.Under the treatment of 1/2lettuce nutrient solution,the content of vitamin C in sweetpotato sprouts was the highest(43.67mg/100g),while the soluble sugar content(22.31 mg/100g)was slightly lower than that of 1/2MS nutrient solution..However,the total yield(291.22 g/kg)under 1/2MS nutrient solution treatment was lower than that of 1/2 lettuce nutrient solution treatment(349.20 g/kg),and its configuration was more complicated in practice.Therefore,1/2 lettuce nutrient solution is considered more suitable for cultivating sweetpotato sprouts.(4)Different sweetpotato varieties and tuber size had a greater impact on the weight of sweetpotato sprouts,but tuber size had no significant difference on the yield of sweetpotato sprouts Therefore,in actual production,the sweetpotato tubers of less than 50 g can be used to produce sweetpotato sprouts,thereby improving the utilization value of the sweetpotato tubers.