Study On The Quality Properties Of Sweet Potato Fish Balls And Its Application

Sweet potato(Ipomoea batatas[L.]Lam),also known as yam,batata and scammony root,is an root tuber of herbaceous sweet potato crops belonging to Ipomoea genus,Convolvulaceae family.Sweet potato is rich in carbohydrate,protein,carotenoid,anthocyanin,conjugate phenolic acid,mineral substance and other nutritional substance,having the effects of antioxidant,anti-cancer,anti-diabetic,anti-inflammatory and so on.Our country is rich in resources for sweet potato,the planting area and production of that both are the first in the world.Currently,the types of sweet potato are varied in the market,but there are few application and studies of sweet potato in the surimi products.Hence,this subject study on the process technologies and quality properties of sweet potato fish balls,aiming to combining the nutritional and medicinal value of sweet potato with fish balls,to develop a new type fish ball with high nutritional value and low glycemic index(GI).The development of sweet potato fish ball could not only expand thinking of new fish ball products,but also able to develop the way to value-added utilization of sweet potato.The major research contents and conclusion are as follows:(1)The effects of 0%?20%sweet potato(on the basis of 100 g Nemipterus virgatus surimi)on the quality of fish balls are studied.The results showed that,sweet potato was rich in several nutritional components,could increase the protein content,fat content,dietary fiber content and decrease the content of total sugar in fish balls production.The addition amount sweet potato higher than 10%could improve the gel strength,hardness,chewiness,viscosity,resilience of carve structure and sensory quality of fish balls;and the GI value of fish balls also significantly decrease from 60.02 to 54.71 compared with control samples,belonging to low GI foods.Indicating that sweet potato fish balls has a good prospect to be the low-GI foods,which could become the desirable food for the people who are diabetics and obese.However,the addition of sweet potato would reduce the springiness and water holding capacity of production,which might be caused by excessive starch.Suggesting processing formula of sweet potato fish balls should be optimized further.(2)The influence of different addiction of soy protein isolates,salt,lard and potato modified starch on the quality of fish balls are analyzed.On basis of single factor test,according to comprehensive score,response surface method was adopted to optimize the formula of soy protein isolates,lard and potato modified starch,got the best formula:Nemipterus virgatus surimi 100 g,sweet potato 10 g,potato modified starch 4 g,soy protein isolates 12 g,trashed ice 100 g,lard 28 g,salt 2.2 g,meringue powder 3 g,seasoning powder 1.5 g,oil 2 g and compound phosphates 0.5 g.With this formula,the sweet potato fish ball got the highest comprehensive score.Compared to traditional fish balls,sweet potato fish ball showed good quality on gel property,texture properties,water holding capacity and nutritional value,especially the rate od starch digestion decreased significantly,which related to high levels of dietary fiber content.(3)During the frozen storage,comparing with control fish balls,sweet potato fish balls could better maintain the gel strength and hardness,and pH fluctuations was much lower.During 6 months frozen storage period,peroxide value(POV),acid value(AV),and bacterial count of the fish balls were all are under the level of National Food Hygiene Standard.The fitted equation between total bacterial count and the storage time could be expressed as:Y2=7058.93*exp(0.0051*x)(R2=0.9642),the predicted shelf-life was 383 d(p>0.05),which did not have the significant differences compared with contrast fish balls(375 d).The sweet potato fish balls got the higher sensory score than control fish balls,suggesting it has the market and potential to develop new fish balls.