| In this study,Naan from Xinjiang was processed by a new electric oven,which replaced the traditional Naan-pit roasting technology.It mainly focused on the effects of Naan processing raw materials and ratios,dough processing methods and baking methods on Naan quality and flavor formation.The production and control of acrylamide during the baking process was evaluated,the influence of packaging and storage conditions on the quality and safety of Naan products and the development of packaging anti-corrosion technology for packaging Naan products were investigated,and the starch digestion characteristics in Naan products was carried.(1)The single factor test of the ratio of basic raw materials includes water,oil,yeast,and salt,and orthogonal optimization experiments were carried out on the basis of single factor.By evaluating Naan's sensory,specific volume,height-diameter ratio and color difference quality,it was shown that the influence of the proportion of basic raw materials on Naan quality was interrelated and mutually restrictive.According to the orthogonal analysis of variance,the order of influence of basic raw materials on Naan quality was: water>oil>salt>yeast.(2)Single factor tests for the basic process conditions of oven-baked Naan include proofing temperature,proofing time,baking temperature,baking time,and number of kneading times.The response surface optimization test was carried out on the basis of single factor.According to the analysis of variance,the proofing temperature had a significant effect on the quality of Naan(P?0.05).The baking temperature and baking time had a significant effect on the quality of Naan(P<0.01).The interaction between proofing temperature and proofing time is extremely significant,and the interaction between baking temperature and baking time is extremely significant.Through the optimization analysis of Design-Expert software,the optimal process conditions were as follows: the proofing temperature was 32.44 °C,the proofing time was 65.67 min,the baking temperature was 319.43 °C,and the baking time was 393.55 s.Finally,the amino acids,flavor substances and Fourier infrared spectra of laboratory-made Naan and commercially available Naan were compared and analyzed.Amino acid comparison analysis showed that all the tested wheat flour and Naan could detect 17 kinds of amino acids,and the total amount of self-made Naan amino acids was higher than the five commercially available Naan,and there were differences between commercially available Naan.According to the flavor analysis,18 volatile substances were detected from the self-made and commercially available Naan samples.Compared with the commercially available Naan,the ketones,esters and organic acids were not detected by the homemade Naan.And the detected volatile substances were less.According to infrared analysis,the infrared absorption peak positions of wheat flour between different brands are basically the same,but the absorption intensity was different.Compared to the commercially available Naan,the self-made Naan had a slightly lower level of protein,fat,carbohydrates,etc.than the commercially available Naan,at an intermediate level.(3)High performance liquid chromatography was used to study the effect of different excipients and different addition ratios on the amount of acrylamide produced in Naan.According to the analysis,with the increase of sesame powder and walnut powder,the amount of acrylamide decreased first and then increased.The addition of soy protein isolate,milk powder and soy flour can significantly inhibit the formation of acrylamide,and the amount of acrylamide formed decreases with the increase of the addition amount.Compared with Naan on the market,the acrylamide was determined.The content of the self-made Naan acrylamide was about 324 ?g/kg,and the content was relatively low.(4)The Naan preservation technology was studied at-20 °C,-4 °C and 25 °C storage conditions and three kinds of packaging methods: ordinary plastic packaging,deoxidation packaging and vacuum packaging.Sensory evaluation,photogrammetry,moisture determination,acid value determination,and microbiological testing were used to evaluate Naan quality changes.Under the storage condition of 25 °C,the vacuum packaging could squeeze the soft Naan,the sensory quality was seriously degraded,the oil was more likely to precipitate,and the spoilage was accelerated,so it was not suitable for the packaging of Naan.Compared to ordinary plastic packaging,deoxidizing packaging shows a greater advantage in extending the shelf life(P?0.05).Storage conditions of 4 °C and-20 °C can be very effective in extending the shelf life.The three packaging methods tend to be consistent at 4 °C and-20 °C.UV sterilization and microwave sterilization before packaging were effective,which can extend the shelf life(P?0.05).(5)Simulated starch digestion in vitro was used to study the digestive properties of starch in Naan,including simulations of saliva,gastric juice,and intestinal fluid.The FG,TS,RDS,SDS,RS,HI,GI,hydrolysis curve,total polyphenols,and total carotenoids of the five samples were measured.From the perspective of the starch hydrolysis rate of the whole curve,ZM and XM were similar,ZN,XN and SN were similar,and the starch hydrolysis rate of steamed bread was significantly higher than that of Naan.The HI and GI of steamed bread were significantly higher than that of Naan.The HI and GI of Naan made from Xinjiang flour were slightly higher than Naan of Zhongyu Flour and Naan which was commercially available.The total phenolic content was 36.17,55.38,29.67,41.46,65.77 mg GAE/100 gDM,respectively.The total carotenoid content in steamed bread was significantly higher than in Naan.The samples made from Xinjiang flour have a slightly higher carotenoid content than the similar samples made by Zhongyu Flour.Among the three Naan products,the SN carotenoid content was higher. |
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