本文關(guān)鍵詞：加工處理方法對(duì)大米性質(zhì)和微結(jié)構(gòu)影響的研究　出處：《安徽工程大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

  更多相關(guān)文章： 工藝優(yōu)化 性質(zhì)變化 微結(jié)構(gòu)變化

【摘要】：方便米飯是由工業(yè)大規(guī)模生產(chǎn)的,在食用前只需簡(jiǎn)單烹調(diào)或直接食用,與普通米飯口感風(fēng)味一致的主食食品。方便米飯的制作需經(jīng)過(guò)浸泡、蒸煮、干燥和殺菌等工藝,這些加工方法引起大米微生物菌落變化,改變了大米微結(jié)構(gòu),造成回生率上升,溶脹能力改變及復(fù)水性差等問(wèn)題。本課題研究了浸泡工藝下大米微生物菌落變化,建立了大米浸泡、微波加熱和蒸煮三種工藝的最佳參數(shù),并利用SEM、XRD、FT-IR、DTA、TGA等方法,表征加工處理前后微結(jié)構(gòu)變化,來(lái)探究大米回生特性,溶脹能力及復(fù)水特性的改變。得到以下結(jié)果:(1)在方便米飯加工方法中,浸泡工藝可以較好的保持米飯風(fēng)味,然而大米含水量的上升也會(huì)引起微生物菌落的大量生長(zhǎng)和回生率的上升。通過(guò)研究發(fā)現(xiàn),隨著浸泡時(shí)間的延長(zhǎng),菌落總數(shù)快速上升,在浸泡7天后菌落總數(shù)超標(biāo),霉菌和酵母的生長(zhǎng)速度明顯小于細(xì)菌的生長(zhǎng)速度。大米的含水量隨浸泡時(shí)間與溫度上升而增大,大米回生率與含水量呈正相關(guān),方便米飯實(shí)際生產(chǎn)應(yīng)用中,浸泡條件為60 min,25℃為最佳工藝參數(shù)。為研究回生率的上升原因,對(duì)大米微結(jié)構(gòu)進(jìn)行表征,發(fā)現(xiàn)大米淀粉微結(jié)構(gòu)出現(xiàn)凹陷和粘連現(xiàn)象,晶體結(jié)構(gòu)依然是A型,然而隨著水進(jìn)入大米內(nèi)部結(jié)構(gòu),大米的氫鍵數(shù)量減少,相對(duì)結(jié)晶度下降后趨于穩(wěn)定,淀粉分子趨向于有序化,加大淀粉回生。(2)在方便米飯加工方法中,微波加熱工藝有快速膨化和殺菌的作用,然而過(guò)度的微波熱效應(yīng)會(huì)引起大米溶脹能力改變,影響人體對(duì)營(yíng)養(yǎng)物質(zhì)的吸收。通過(guò)研究發(fā)現(xiàn),大米的溶脹能力隨含水量上升而上升,隨微波功率增加溶脹能力先上升后下降。方便米飯實(shí)際生產(chǎn)應(yīng)用中,浸泡60 min,在464 W下微波加熱10 min為最佳的大米微波處理工藝參數(shù)。為研究溶脹能力變化原因,對(duì)微波處理前后的大米進(jìn)行表征,發(fā)現(xiàn)大米淀粉微結(jié)構(gòu)出現(xiàn)凹陷現(xiàn)象,晶體結(jié)構(gòu)屬于A型,在微波熱效應(yīng)下,淀粉內(nèi)部結(jié)構(gòu)發(fā)生斷裂,還原性羥基與水結(jié)合能力上升,大米的氫鍵數(shù)量減少,相對(duì)結(jié)晶度較處理前下降并趨于穩(wěn)定,淀粉分子穩(wěn)定性上升,溶脹能力加強(qiáng)。(3)在方便米飯加工方法中,蒸煮工藝可以保存大米營(yíng)養(yǎng)又提高風(fēng)味,然而蒸煮條件的改變也會(huì)引起營(yíng)養(yǎng)流失,感官品質(zhì)下降等問(wèn)題。通過(guò)研究發(fā)現(xiàn),大米的復(fù)水特性隨米水比和蒸煮時(shí)間呈波浪形變化,方便米飯工藝中,米水比1:7蒸煮7.0 min為較好保持大米復(fù)水特性工藝參數(shù)。為研究復(fù)水特性變化原因,對(duì)大米微結(jié)構(gòu)進(jìn)行表征,發(fā)現(xiàn)大米表面和剖面微結(jié)構(gòu)出現(xiàn)海綿狀結(jié)構(gòu),在蒸煮工藝下,溫度的上升使淀粉脂類(lèi)復(fù)合物逐漸形成,結(jié)晶區(qū)域被破壞,相對(duì)結(jié)晶度下降,水進(jìn)入淀粉內(nèi)部,引起淀粉分子間的氫鍵斷裂,溫度與水雙方面作用使復(fù)水特性發(fā)生波浪式變化。
[Abstract]:Instant rice is produced in a large scale by industry. It only needs simple cooking or direct consumption before eating. It is a staple food with the same taste as common rice. The preparation of instant rice needs to be soaked and cooked. Drying and sterilization technology, these processing methods caused changes in the microbial colony of rice, changed the rice microstructure, resulting in an increase in the rate of regrowth. The change of microbial colony of rice under soaking process was studied. The optimum parameters of rice soaking, microwave heating and cooking were established, and SEM was used. Methods such as XRDX FT-IRT-DTA-TGA were used to characterize the microstructure changes before and after processing in order to explore the characteristics of rice retrogradation. The change of swelling ability and rehydration characteristics. The following results were obtained: 1) in the processing method of instant rice, the steeping process could better maintain the flavor of rice. However, the increase of rice water content will also cause a large number of microbial colonies to grow and the rate of regrowth. Through the study, it is found that with the extension of soaking time, the total number of colonies increases rapidly. After soaking for 7 days, the total number of colonies exceeded the standard, and the growth rate of fungi and yeast was obviously lower than that of bacteria. The water content of rice increased with the soaking time and temperature, and the rate of rice regrowth was positively correlated with the water content. In the practical application of instant rice, the optimum technological parameter was 60 min ~ 25 鈩，

本文編號(hào)：1375550