双歧杆菌纯种发酵胡萝卜汁牛乳工艺研究

以健康人体中选育出的发酵活力高、耐氧性和抗逆性强的优良发酵菌株--长双歧杆菌(Blm)为试验菌株,研究了接种量、基质起始pH值、发酵温度、氧等因素对Blm在胡萝卜汁牛乳中发酵的凝乳时间、活菌含量、pH值和感官质量的影响;利用正交试验优化并确定了Blm发酵的最佳工艺条件在胡萝卜汁牛乳培养基(添加250 mL/L胡萝卜汁和50 g/L蔗糖的牛乳培养基)中,接种量5×107 cfu/mL,基质起始pH值7.0,发酵温度39℃,有氧发酵.产品凝乳时间在5 h内,双歧杆菌活菌数在1×109 cfu/mL以上,pH值5.0.制备的胡萝卜汁双歧杆菌酸乳呈橙黄色,组织状态致密,无乳清析出,且综合了双歧杆菌、胡萝卜、牛乳的功能特性,集风味、营养、保健功能于一体.     

双歧杆菌与乳酸菌混合发酵胡萝卜汁牛乳饮料的工艺研究

以从健康人体中选育出的发酵活力高、耐氧性和抗逆性强的优良发酵菌株长双歧杆菌(Blm)作为主要试验菌株,以乳酸菌保加利亚乳杆菌(L.b-DR)和嗜热链球菌(S.t-3)作为辅助菌株,研究了接种量及菌种配比、基质起始pH值、发酵温度、氧气等因素对双歧杆菌与乳酸菌混合发酵胡萝卜汁牛乳饮料时,对凝乳时间、活菌含量、pH值和产品感官风味的影响。利用正交试验优化并确定了Blm与乳酸菌混合发酵的最佳工艺条件,即在胡萝卜汁牛乳培养基(25%胡萝卜汁和5%蔗糖)中,总接种量3%(3×107cfu/mL),其菌种配比为Lb-DR∶St-3∶Blm=1∶1∶1,基质起始pH值7.0,发酵温度39℃,有氧条件发酵。产品凝乳时间在3.33 h,pH值为4.5左右,总活菌数可达1×109cfu/mL以上,橙黄色,组织状态致密细腻,无乳清析出。对该产品的工艺条件探究,为开发其它功能性益生菌乳制品提供了新的思路和方法。     

胡萝卜汁双歧杆菌发酵饮料的研制

在添加 5 %脱脂牛乳和 4%～ 5 %蔗糖的胡萝卜汁中接种 5× 1 0 6 /mL的长双歧杆菌 (Bifi dobacteriumlongum) ,发酵 1 0～ 1 4h后或终点pH达到 4 2左右时 ,可获得总菌数在 1 0 9/mL数量级、色泽鲜艳、口感良好、风味上佳的双歧杆菌胡萝卜汁发酵饮料制品。产品低温贮运的保质期为1周左右。     

乳酸发酵胡萝卜汁的研制

以胡萝卜汁为基质,对若干乳酸发酵菌株进行发酵性能及生长曲线的研究,确定了以嗜酸乳杆菌为主要发酵菌种.并使之与耐氧驯化的青春双歧杆菌混合培养,表现出良好的共发酵特性.在胡萝卜汁中加入食盐1%,蔗糖2%,豆浆7%,接种量1%,种间比(La∶Ba)1∶1,在37℃下发酵24h,活菌总数可达1.2×109个/ml.以此培养液为发酵剂,对胡萝卜汁进行发酵,即可制得色泽纯正、风味优良、质地细腻的乳酸发酵胡萝卜汁.最佳发酵参数为接种量2%,砂糖4%,食盐0.3%,37℃,16h.     

双歧杆菌发酵胡萝卜汁饮料的研制

采用已耐氧驯化的两歧双歧杆菌与普通乳酸菌共同发酵胡萝卜汁制得发酵饮料。通过正交试验确定的最优发酵条件为:发酵温度39℃,发酵时间9h,胡萝卜汁浓度27％,乳糖添加量1％,双歧杆菌接种量7％,乳酸菌接种量1％。用此条件所得产品中双歧杆菌和乳酸菌活菌数分别达6.5×10~7cfu/mL和1.7×10~8cfu/mL。该产品是色、香、味俱佳的天然营养保健制品。     

乳酸发醇胡萝卜汁的研制

以胡萝卜汁为基质,对若干乳酸发酵菌株进行发酵性能及生长曲线的研究,确定了以嗜酸乳杆菌为主要发酵菌种。并使之与耐氧驯化的青春双歧杆菌混合培养,表现出良好的共发酵特性。以此培养液为发酵剂,对胡萝卜汁进行发酵,即可制得色泽纯正、风味优良、质地细腻的乳酸发酵胡萝卜汁。     

胡萝卜汁双歧杆菌酸奶的研制

采用已耐氧驯化的两歧双歧杆菌,与普通乳酸菌共同发酵含胡萝卜汁的牛奶制品。试验选定了胡萝卜汁的最佳添加量,并确定生产工艺为：双歧杆菌与乳酸菌以5：3比例添加到含25％胡萝卜汁的牛乳中,于39℃发酵4．5h。制品中双歧杆菌活菌含量达107个／ml以上,风味与普通酸奶类似,营养保健价值远高于普通酸奶。     

双歧杆菌发酵胡萝卜汁酸乳贮藏稳定性研究

从健康人体中选育出2株发酵活力高、耐氧性和抗逆性强的双歧杆菌优良发酵菌株两歧双歧杆菌Bbm和长双歧杆菌Blm作为试验菌株,制备了双歧杆菌纯种及双歧杆菌与乳酸菌混种发酵胡萝卜汁酸乳,考察了发酵产品在室温(20~30℃)和冷藏(0~4℃)条件下的贮藏稳定性。试验结果表明:0~4℃冷藏21d,活菌含量仍可达1×109cfu/mL以上,pH值降至4.2~4.3,酸甜适宜。因此,确定发酵产品0~4℃下贮藏期为21d。     

胡萝卜汁双歧杆菌酸乳发酵培养基优化研究

本文以从健康人体中选育出2株发酵活力高、耐氧性和抗逆性强的优良发酵菌株两歧双歧杆菌Bbm和长双歧杆菌Blm作为试验菌株,研究了胡萝卜汁和蔗糖在牛乳中的添加量对双歧杆菌在牛乳中发酵的凝乳时间、凝乳时活菌数及pH值、产品感官风味的影响,确定了发酵培养基中胡萝卜汁和蔗糖的最适添加量分别为20%～30%和5%～6%,完成了以胡萝卜汁乳作为双歧杆菌最佳载体的初步探索,为功能性益生菌乳制品的研制和开发提供了必要条件.     

胡萝卜汁的加工特性

分析了胡萝卜的营养成分及价值,概述了其用于加工制汁的工艺条件,分析了它在加工制汁及贮藏中的常见问题,并提出了相关的解决措施.     

冬枣酸奶加工工艺研究

以鲜乳为原料,经乳酸菌发酵制成凝固型酸牛奶后,添加一定比例的冬枣汁搅拌、冷却罐装,即得风味清香、口感好、营养价值丰富的合格的搅拌型冬枣汁酸奶.经研究得:接种菌种为保加利亚乳杆菌和嗜热链球菌(按1:1比例),接种量为3%～5%,发酵温度和发酵时间的最佳组合为41℃～42℃、3 h～4h.     

枣汁营养酸奶的工艺研究

以枣汁和脱脂奶粉为主要原料,选用适当的乳酸菌进行发酵,研制出具有浓郁枣香和乳香风味的双重营养和保健作用的枣汁酸奶.通过正交试验和对比实验对枣汁酸奶的配方和加工工艺进行了研究,得出最佳配料及发酵条件为:枣汁20%,白砂糖7%,酸奶稳定剂0.25%,发酵温度为38℃,接种量3%,发酵时间12 h～14 h.     

THE EFFECT OF PROCESSING METHOD ON THE CHARACTERISTICS OF CARROT JUICE

ABSTRACT

The production of carrot juice using different technologies is the main subject of this investigation. Although the production and preservation of the carrot juice technology have not been improved and are not prevalent, an intensive study has been carried out on this subject recently. In this study, the effects on the yield and quality of carrot juice produced with and without total enzymatic liquefaction (Pectinex Ultra SP‐L, Novo Nordisk Ferment, Dittingen, Switzerland) as well as lactofermentation or citric acid addition have been investigated. Generally, enzymatic liquefaction of mash increased the juice yield (89.32 ± 1.17 and 90.43 ± 0.47% for lactofermented and citric‐acid‐added samples, respectively), while the control sample juice yield was found to be 59.90 ± 0.81%. Lactofermented and acid‐added samples demonstrated lower pH value. In enzyme‐treated samples, the total acidity increments were also determined. Accordingly, galacturonic acid formed after enzymatic breakdown of pectin in the raw material increased the total acidity of the samples. Magnesium contents of lactofermented juices were found to be low because lactic acid bacteria require magnesium for their growth. β‐Carotene contents have been found to be higher in both lactofermented and in nonenzyme‐treated samples.

PRACTICAL APPLICATIONS

This article describes the effects of different processing methods on the characteristics of carrot juice. It is difficult to preserve vegetable juices such as carrot juice because of their low acidity. The acidity of carrot juice (pH ～6.2) can be adjusted by the addition of citric acid or the lactofermentation method to pH 4.5. With these processes carrot juice can be preserved by pasteurization as occurs for low pH fruit juices, increasing shelf life. According to the results of this study, increasing the acidity of mash with lactofermentation or citric acid addition also increases the juice yield.

     

STABILIZATION OF CARROT JUICE BY DILUTE ACID TREATMENT

SUMMARY– A problem arises if juice extracted from raw carrots is heated to about 180° before or during conventional canning practices. An unsightly, unappetizing coagulum forms and the color of the juice precipitates with the coagulum. The coagulum is not as evident if the carrots are heated 5 min in water prior to juice extraction, but the juice loses some of its bright-orange color. The canned juice extracted from carrots heated 5 min in a .05 N acetic acid solution does not coagulate and the amount of juice which can be extracted from the carrots is 3.3% greater than that from carrots heated 5 min in water. The centrifuged juice from acid-treated carrots had a brighter orange color than juice from the water-treated carrots. The color notation was Rd, 23.7, a, 30.4 and b, 34.8 for juice from acid-treated carrots compared with a notation of Rd, 19.2, a, 24.4 and b, 31.4 for the juice from water-treated carrots. The canned juice extracted from raw carrots had less pectic substances and starch and about the same amount of protein as the canned juice from the carrots heated in water or .05 N acetic acid, but the canned juice from raw carrots coagulated. The juice from carrots heated in acid does not form a coagulum and maintains its orange color, probably because of the action of the heat and acid on the protoplasmic liquid of the cell before or immediately after the cell is ruptured.     

南瓜汁酶法制取工艺研究

对南瓜热烫方式进行单因素试验，优选最佳酶制剂，确定了酶解最佳工艺参数组合。单因素试验表明：0．3％的醋酸溶液，热烫10min，料水比1g：3mL打浆对南瓜出汁率和固形物含量的效果最好。确定纤维素酶是最佳酶制荆。对酶解参数进行正交试验，结果表明：加酶量为70mg/L，pH值为5,5，温度为50℃和时间为1h效果最佳。     

THE EFFECTS OF DIFFERENT INITIAL LACTOBACILLUS PLANTARUM CONCENTRATIONS ON SOME PROPERTIES OF FERMENTED CARROT JUICE

Carrot juice (Daucus carota L.) is one of the most popular vegetable juices and represents a rich source of natural β‐carotene. Vegetable juices are available either fermented or not fermented. With the production of lactofermented juices, carrot juices are microbiologically stable, delicious and potentially provide high nutritional value. In this study, Refik Saydam Kulfur Kolleksiyanu (RSKK) 1602 Lactobacillus plantarumis used as a starter culture in carrot mash. Sensory evaluation demonstrated that an initial bacteria concentration of 3 × 10⁵ cfu/g mash resulted in the most preferred fermented carrot juice. The acidity of the fermented carrot juice can be adjusted by altering the population of the starter RSKK 1602 L. plantarum culture and the 15–16 h of fermentation time. A modified Gompertz equation was selected to describe the growth curve of RSKK 1602 L. plantarum in carrot mash.     

THERMAL STABILITY OF BLACK CARROT ANTHOCYANINS IN BLOND ORANGE JUICE

Abstract Blond orange juice was colored with black carrot concentrate as an alternative to blood orange juice. Thermal stability of anthocyanins from black carrots in orange juice was determined at 70, 80 and 90C. Anthocyanin degradation in colored blond orange juice followed to first-order reaction kinetics. As expected, the degradation rate was dependent on temperature, being faster at higher temperatures. Half-lives for anthocyanin degradation were 12.5, 6.3 and 3.1 h at 70, 80 and 90C, respectively. Between 70–90C, activation energy was 72.03 kJ mol^-1. Results showed that coloring blond orange juice with black carrot concentrate resulted in a much more stable product as compared with blood orange juice.     

石榴浓缩清汁产业化技术研究

介绍了石榴浓缩清汁产业化生产工艺、加工技术及相应的产品质量标准.选用目前国际先进设备,采用此项加工技术,可生产营养损失少、具有天然风味的石榴浓缩清汁.     

雪莲果、西红柿和胡萝卜复合果蔬汁的研制

以雪莲果、西红柿、胡萝卜3种汁液为原料生产复合果蔬汁,通过正交试验筛选出一组最佳果蔬汁配比.结果表明:雪莲果汁40mL、番茄汁20mL、胡萝卜汁15 mL、白砂糖10%、柠檬酸为0.2%时混合为最佳配比.