【摘要】：紅棗(Ziziphus jujuba dates),又稱大棗,是一種鼠李科(Rhamnaceae)棗屬植物(Ziziphus jujubaa Mill)的成熟果實,原產(chǎn)于我國黃河流域,已經(jīng)有3000多年的栽培歷史。據(jù)中國統(tǒng)計年鑒統(tǒng)計,2012年我國紅棗產(chǎn)量已經(jīng)達(dá)到588萬噸,占世界紅棗產(chǎn)量95%以上,并且每年仍保持著10%以上的年增長率增長。目前,除少量紅棗鮮食外,大部分被加工成干棗被直接消費或干制后作為其他產(chǎn)品加工的原料。在紅棗精深加工中,常用乙醇萃取棗酊、水提醇沉制備紅棗多糖和堿液提取紅色素,但加工過后的紅棗殘渣并未進(jìn)行二次、三次利用,造成了極大的浪費。因此,本文提出分步萃取技術(shù),依次進(jìn)行紅棗中棗酊、多糖及色素的提取分離,使紅棗資源得到充分利用。主要研究結(jié)論如下1.以棗粉為原料,對主要營養(yǎng)成分進(jìn)行測定,各組分含量結(jié)果如下:還原糖56.64%、水分18.04%、粗纖維4.21%、灰分3.25%、蛋白質(zhì)2.89%、粗脂肪4.21%;對棗酊萃取工藝進(jìn)行溫度(40、50、60、70℃、時間(1、2、3、4 h)和料液比(1:20、1:15、1:10、1:5 g/mL)的三因素四水平實驗,獲得了最佳萃取工藝:萃取溫度60℃C、時間2 h、料液比1:10 g/mL,該工藝下獲得棗酊感官品質(zhì)最佳,其總糖含量49.5%、乙醇含量17.84%、含膏量47.38%,提取率達(dá)47.38%,并通過GC-MS從棗酊中鑒定出35種揮發(fā)性成分。2.以經(jīng)95%乙醇提取過后的紅棗殘渣為原料,對提取溫度(60、70、80、90℃)、時間(1、2、3、4 h)和級數(shù)(1、2、3級)等因素進(jìn)行研究,獲得了棗酊殘渣多糖提取的最佳工藝:溫度80℃、時間2 h,該條件下多糖得率3.02%,且提取三次提取率可達(dá)98.32%。并以紅棗多糖、氨基酸為原料,褐變程度、顏色、pH值變化、揮發(fā)性成分及感官評分為指標(biāo),探討了溫度(100、120、140℃)和時間(0.5～5 h)對紅棗多糖美拉德反應(yīng)的影響。結(jié)果表明:隨著反應(yīng)時間的延長,A420 nm增大、色差值先增大后減小、pH值升高、產(chǎn)物褐變程度加深,且溫度越高影響越大。溫度和時間均對美拉德反應(yīng)產(chǎn)物的感官特性具有極顯著影響(p0.01),120 ℃和14℃處理產(chǎn)生的揮發(fā)性物質(zhì)種類比100 ℃處理更為豐富,當(dāng)高溫處理時間低于3.5 h,浸提液揮發(fā)性物質(zhì)主要為3,6,9,12-四氧十四烷-1-醇、甲氧基乙酸乙酯和4,8-二甲基十一烷,超過3.5 h則以十四烷和十九烷為主。此外,120℃熱處理2.5～3.5 h對浸提液感官特性和香氣成分的形成最為有利。最終,反應(yīng)產(chǎn)物的整體喜好度、香氣強(qiáng)度、香氣持久性、甜香、烤香、焦苦評分分別與10、14、13、14、4、14種揮發(fā)性物質(zhì)具有統(tǒng)計顯著(p0.05)的相關(guān)性,以這些物質(zhì)為自變量建立回歸模型可對樣品的整體喜好度、香氣強(qiáng)度、香氣持久性、甜香、烤香、焦苦的評分進(jìn)行很好地預(yù)測。3.以提取紅棗多糖的殘渣為原料,A272 nm為指標(biāo),對氫氧化鈉濃度、超聲溫度、時間、功率、料液比等因素進(jìn)行研究。獲得了紅棗色素提取的最優(yōu)工藝:料液比1:15 g/mL、超聲溫度70 ℃、時間40 min、功率76 W,該條件下紅棗色素得率為6.30%,各因素影響的顯著性大小:料液比超聲溫度超聲時間超聲功率;堿溶劑提取的最佳溫度80 ℃,時間40 min,紅棗色素提取率為2.40%。研究表明采用乙醇、水、堿液可實現(xiàn)分步提取紅棗中香精、多糖及色素,能夠充分利用紅棗資源,將三者利用率換算成原始紅棗粉末其總利用率達(dá)56.70%。
[Abstract]:Red date, also known as jujube, is a mature fruit of the genus Rhamnaceae, native to the Yellow River basin of our country, and has more than 3000 years of cultivation history. According to the statistics of China's Statistical Yearbook, the output of red jujube in China has reached 588.8 million tons in 2012, accounting for over 95% of the world's red date production, and the annual growth rate of more than 10% is still maintained. At present, in addition to a small amount of red date fresh food, most of the raw materials processed into dry date are directly consumed or dried as raw materials for processing other products. In the deep processing of red dates, the red jujube polysaccharide and the alkali liquor are extracted with ethanol to extract the red date polysaccharide and the alkali liquor to extract the red pigment, but the processed red date residue is not subjected to secondary and tertiary utilization, thus causing great waste. Therefore, the extraction and separation of jujube tincture, polysaccharide and pigment in red date were carried out in order to make red date resources fully utilized. The main findings are as follows. The main nutritional components were determined with jujube powder as raw material, and the contents of the components were as follows: reduction sugar 56. 64%, moisture 18. 04%, crude fiber 4.21%, ash 3.25%, protein 2.89%, crude fat 4.21%, and temperature (40, 50, 60, 70 鈩，

本文編號：2281901