| Maren sugar is a traditional specialty food in Xinjiang.Its main raw materials are local walnuts and syrup.Maren sugar is easy to deform and soften at high temperature;Among them,the oil is easy to oxidize during storage and sale,which leads to the spoilage of products.In order to improve the solid shape of Maren sugar and inhibit the oxidation of walnut oil in Maren sugar,the production technology of Maren sugar was improved,and natural antioxidants were added and the product packaging was changed.By studying the effects of the proportion of white granulated sugar in syrup,the proportion of syrup and the proportion of egg white on sensory evaluation score and texture,response surface model was established to optimize the production process of Maren sugar and obtain better quality products.Sensory,physicochemical and microbial indexes of different kinds of marzipan were detected,and the effects of two kinds of natural antioxidants(carrot powder,grape seed extract)and packaging methods on antioxidant activity of marzipan were explored by oven accelerated test.The main contents and conclusions are as follows:1.Improve the production process of Maren sugar,optimize the ratio of raw materials for Maren sugar production,and improve the solid shape of products.By baking walnut,the proper baking conditions were selected to increase the aroma of walnut.The sensory evaluation method of Maren sugar was improved,and the optimal raw material ratio of Maren sugar was optimized by single factor response surface methodology.The effects of white granulated sugar ratio,boiled syrup ratio and egg white addition amount on sensory and texture were analyzed.The results showed that white granulated sugar had great influence on hardness and brittleness of Maren sugar,while the ratio of boiled syrup to walnut had great influence on hardness,chewiness,brittleness and stickiness,while egg white content mainly affected hardness,brittleness and stickiness.When the optimized raw material ratio is adjusted to 55% white sugar in syrup,54% syrup and 2% egg white,the sensory score is better.2.Inhibition of natural antioxidants on the oxidation of marzipan and comparison of shelf life prediction.The antioxidant substance of carrot freeze-dried powder is mainly?-carotene,and its content is 13.1 mg/100 g by high performance liquid chromatography The main antioxidant of grape seed extract is oligomeric procyanidins,the content of which is 98.7%.The DPPH method and hydroxyl radical method showed that carrot freeze-dried powder and grape seed extract had good antioxidant capacity.The two substances were added to walnut according to different concentration gradients.According to the results of accelerated storage experiment,considering the cost and antioxidant effect,the most suitable additive was 0.15% of walnut mass.The peroxide value,acid value and malondialdehyde content of the three samples during storage in different packages were detected to compare the effects of antioxidant substances,and the shelf life of the products was predicted by oven method.The results showed that the shelf life of marzipan added with grape seed extract and carrot freeze-dried powder increased by 1.8 and 1 month,respectively,to 10.3 and 9.5 months.3.Quality analysis of Maren sugar products.The water content,protein content and fat content of the three kinds of Maren sugar products meet the local and national standards.After detection,the total number of colonies was < 200 CFU/g;Coliform group< 10cfu/g;No pathogenic bacteria were detected,and they all met the national standards. |
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