Effects of Commercial-scale Pulsed Electric Field Processing on Flavor and Color of Tomato Juice

Effects of commercial‐scale pulsed electric field (PEF) processing on the flavor and color of tomato juice during storage at 4 deg;for 112 d were studied. Tomato juice was prepared by hot break at 88°C for 2 min and then thermally processed at 92° for 90 s or PEF processed at 40 kV/cm for 57 μs. The PEF‐processed tomato juice retained more flavor compounds of trans‐2‐hexenal, 2‐isobutylthiazole, cis‐3‐hexanol than thermally processed or unprocessed control tomato juice (P < 0.05). PEF‐processed juice had significantly lower nonenzymatic browning and higher redness than thermally processed or control juice (P < 0.05). Sensory evaluations indicated that the flavor of PEF‐processed juice was preferred to that of thermally processed juice (P < 0.01).     

番茄汁乳酸菌发酵饮料的研制

以番茄酱为原料,按一定比例稀释后,经乳酸菌发酵而制成番茄汁乳酸菌发酵饮料,通过对接种量、发酵时间、发酵温度、风味、稳定性进行实验,从而确定出最佳工艺参数为:接种量5％,发酵温度40℃,发酵时间30h,黄原胶0.03％,CMC-Na0.02％。     

番茄饮料中番茄红素的检测及稳定性研究

对番茄饮料中番茄红素的提取和分析方法进行了研究。测定了市售5种番茄饮料,确定了番茄饮料中番茄红素以石油醚为提取溶剂,超声波辅助提取法为最佳提取方法,回收率91%;分别用分光光度法和高效液相色谱法作为定量分析方法,并进行了比对。试验还对番茄饮料中的番茄红素稳定性进行了研究,结果表明:番茄饮料中的番茄红素在常温和冷藏条件下比较稳定,而番茄红素溶液在紫外光照下易损失。     

Chemical Characterization of Tomato Juice Fermented with Bifidobacteria

Abstract: The objective of this research was to characterize the chemical properties of tomato juice fermented with bifidobacterial species. Tomato juice was prepared from fresh tomatoes and heated at 100 °C prior to fermentation. Bifidobacterium breve, Bifidobacterium longum, and Bifidobacterium infantis were inoculated in tomato juice and kept at 35 to 37 °C for up to 6 h. Fructooligosaccharide (FOS) was added to tomato juice prior to fermentation. The analyses for brix, total titratable acidity (TTA), pH, color, and lycopene content were conducted to characterize tomato juices fermented with bifidobacterial species. Heat treatment of tomato juice did not cause any significant changes in brix, pH, and TTA. Only the redness of tomato juice was significantly increased, as the heating time increased to 30 min. The tomato juices fermented with B. breve and B. longum exhibited significant decreases in pH (3.51 and 3.80, respectively) and significant increases in TTA (13.50 and 12.50, respectively) (P < 0.05). B. infantis did not cause any significant change in the chemical properties of tomato juice. The addition of FOS further improved the fermentation of tomato juice by bifidobacterial species. The lycopene contents of tomato juice were significantly increased from 88 to 113 μg/g by heat treatment at 100 °C (P < 0.05), however did not exhibit any significant change after fermentation with bifidobacterial species.     

提高番茄浓缩汁中番茄红素含量研究

以番茄为原料，采用多因素正交试验，优化番茄浓缩汁加工工艺条件。本文对番茄浓缩汁加工过程中，对影响番茄红素稳定性的浓缩终点可溶性固形物浓度、杀菌时间、防腐剂加量等因素进行了研究。结果表明，番茄榨汁时加入0．7％NaCl，出汁率最高(68％)；番茄汁浓缩的真空度为87～93kPa、温度50℃、浓缩至可溶性固形物含量23％、杀菌时间10min、防腐剂加量0.0％，在保藏1星期后，番茄红素的含量为97．20μg/100g，维生素C的含量为5．85mg／100g。影响浓缩汁中番茄红素含量的主要因素是浓缩终点的可溶性固形物浓度，其次是杀菌时间。     

番茄汁饮料品质改良技术研究

本文探讨了番茄汁饮料加工过程中的几个关键技术点：1．番茄的破碎方法对番茄汁粘度的影响；2．防止产品分层不稳定现象；3．口感的改良及其最佳配方工艺参数的确定。结果表明，采用85℃、30s热破碎榨汁工艺，0．3％茶多酚作护色剂，以8％蔗糖，0．25％柠檬酸，0．13％复合稳定剂，65％原汁含量为配方组成，可得到品质优良的番茄汁饮料产品。     

取汁方式对热破碎番茄汁品质的影响

研究了2种取汁方式在不同的热处理条件下对热破碎番茄汁品质的影响。结果表明,破碎-加热-打浆取汁方式(简称为BHJ)的番茄汁粘度、果胶含量和番茄红素含量显著高于打浆取汁-加热的取汁方式(简称为JH),但取汁方式对汁的色差影响不大。在本试验范围内,BHJ取汁的番茄汁品质优于JH取汁。     

新疆家蚕抗菌肽在番茄汁加工中的应用研究

本文研究了新疆家蚕抗菌肽的耐热性及其对部分微生物的最小抑菌浓度,和其在不同pH值条件下的溶解度及抑菌效果。并在此基础上进行正交试验,得到将其应用于番茄汁加工中的最佳工艺条件,抗菌肽的添加可降低番茄汁的杀菌强度,提高产品品质,为工业化生产应用提供科学依据。     

苯甲酸钠保藏番茄汁的评价研究

本文探讨了苯甲酸钠和冷藏相结合的方法对番茄汁保藏的具体影响。试验结果表明：在7—8周的贮藏过程中，对照样品可溶性固形物下降20%，还原糖下降60%以上，出现严重发酵酒味。添加0．09%苯甲酸钠的样品可溶性固形物下降很小，还原糖下降约35％左右，风味色泽变化不大。所有样品维生素C含量、菌落总数均有较大下降，添加苯甲酸钠的样品下降更大，说明苯甲酸钠具有较强的抑菌效果，但影响维生素C的保存。冷藏番茄汁时，添加0．06—0．09%的苯甲酸钠较为合适。     

2450MHz频率微波加热条件下番茄汁杀菌特性的研究

本研究选用番茄汁作为研究对象,使用频率为2450MHz的微波进行加热,以时间、功率以及样品的含糖、含盐浓度作为参数,考察样品的升温模式、杀菌效果以及番茄汁的品质指标.本研究中,热效应为微波致死微生物的主要原因.添加糖和盐的样品,经微波处理后,微生物的致死率发生显著变化.微波处理后的样品,L*(亮度)增加,a*(红度)下降,番茄红素测得值增加,较传统巴氏杀菌更好的保留了VC.     

应用响应面法优化无糖番茄鲜汁配方

为探究一种无糖番茄鲜汁的最佳配方,以加工番茄鲜汁为基质,采用单因素和响应面分析法,考察木糖醇添加量、罗汉果甜苷添加量和甜菊糖添加量对无糖番茄鲜汁感官评分的影响。在单因素试验基础上,通过响应面优化试验,得到最佳配方。结果表明,无糖番茄鲜汁最佳配方为:木糖醇添加量1%、罗汉果甜苷添加量0.004%、甜菊糖添加量0.002%,验证试验得到实际感官评分平均值为96.33±0.29分,与理论预测值相比,其相对误差约0.08%。经检测无糖番茄鲜汁的可溶性固形物含量5.6%、番茄红素含量6.29 mg/100 g;菌落总数、大肠菌群及致病菌检测结果均符合农业行业标准。试验结果为无糖番茄鲜汁工业化生产提供理论依据。     

Inactivation Kinetics of Tomato Juice Lipoxygenase by Pulsed Electric Fields

ABSTRACT: Pulsed electric field (PEF) inactivation models for tomato juice lipoxygenase (LOX) were studied. Tomato juice was treated by PEF with the combinations of electric field strength (0, 10, 15, 20, 30, 35 kV/cm), PEF treatment time (20, 30, 50, 60, 70 μs), and PEF treatment temperature (10, 20, 30, 40, 50 °C). The first-order inactivation models, Hulsheger's model, Fermi's model, and the 2nd-order polynomial equation adequately described the LOX inactivation. Calculated D values were 161.0, 112.9, 101.0, and 74.8 μs at 15, 20, 30, and 35 kV/cm, respectively, at 30 °C. The activation energy for the inactivation of LOX by PEF was 35.7 kJ/mol. Applied electric field strength was the primary variable for the inactivation of LOX.     

不同处理方法对番茄汁挥发性组分的影响

运用TCT GC MS联用仪检测纳滤浓缩、冷冻浓缩、真空蒸发浓缩以及超滤澄清处理对番茄汁挥发性成分的影响。实验结果表明,冷冻浓缩番茄样品存留了番茄原汁中主要挥发性成分的18 32 % ,纳滤浓缩样品中存留了16 0 8% ,真空蒸发样品中存留了6 0 5 % ,截留相对分子质量为10万的超滤澄清液存留了番茄原汁中原有挥发性成分的76 12 % ;协调性分析结果表明,与纳滤和真空蒸发处理比较而言,超滤澄清和冷冻浓缩处理对番茄汁协调性的影响较小;与其他浓缩样品相比较,番茄汁的主要挥发性成分己烯醛和己醛在冷冻浓缩的番茄样品中保留的最高。     

Citric Acid and Antimicrobials Affect Microbiological Stability and Quality of Tomato Juice

Acidification, addition of dimethyl dicarbonate and a mixture of potassium sorbate and sodium benzoate and storage temperature were related to microbiological stability and quality of tomato juice. Whether iuices were acidified CDH 4.0 to 3.7) or nonacidified. dimethyl dicarbonate and sorbate/benzoate were highly effective in diminishcng mold and yeast count at 5°C and 20°C. Dimethyl dicarbonate in juices acidified to pH 3.7 and stored at 5°C was most effective in controlling plate counts, followed by sorbate/benzoate in juices acidified to pH 3.7 and stored at 5°C and 20°C. Tomato juice treated with dimethyl dicarbonate had lower amounts of ascorbic acid, total amino acids, fructose, glucose, lycopene and β-carotene.     

胡萝卜、番茄、黄瓜和西芹制汁过程中酶解工艺的优化

目的:优化胡萝卜、番茄、黄瓜和西芹这四种蔬菜制汁的酶解工艺。方法:榨汁过程中分别添加果胶酶或纤维素酶对蔬菜汁进行酶解处理,以出汁率和浊度为指标对酶解条件(酶解时间、酶添加量、酶解温度)进行单因素分析和正交实验优化。结果:四种蔬菜汁的最佳酶解工艺条件为:胡萝卜汁酶解时间60 min,果胶酶添加量0.4%,酶解温度40 ℃,在此条件下出汁率达到84.7%,浊度为54.3 NTU;番茄汁酶解时间40 min,果胶酶添加量0.2%,酶解温度40 ℃,在此条件下出汁率达到95.1%,浊度为36.3 NTU;黄瓜汁酶解时间60 min,果胶酶添加量0.5%,酶解温度40 ℃,在此条件下出汁率达到93.2%,浊度为60.7 NTU;西芹汁酶解时间60 min,纤维素酶添加量0.4%,酶解温度40 ℃,在此条件下出汁率达到92.1%,浊度为33.3 NTU。结论:在最佳酶解工艺条件下制得的蔬菜汁色泽清亮、甘甜爽口,具有一定的开发价值,可用于制备复合果蔬或蔬菜饮料的原料。

     

超声波和巴氏杀菌后樱桃番茄汁的品质变化动力学

以鲜榨樱桃番茄汁为原料,研究其分别经巴氏杀菌（85 ℃、15 min）和超声波杀菌（200 W、40 ℃、30 min）后的品质动力学变化。杀菌后的樱桃番茄汁分别贮藏在不同温度条件下（0、4、10、15、20 ℃）,每隔一定时间测定其色泽、VC含量和菌落总数。结果表明：2 种杀菌方式后樱桃番茄汁的色泽随着贮藏时间的延长和贮藏温度的升高变化越明显;以VC含量变化为指标,在0～10 ℃条件下,超声波杀菌比巴氏杀菌的货架期延长了3.8～4 d;以菌落总数为评价指标,2 种杀菌方式的货架期差异不显著,菌落总数的变化符合一级反应模型,该模型可准确预测0～20 ℃各贮藏温度条件下的货架期。鲜榨樱桃番茄汁在0～10 ℃条件下贮藏,经超声波杀菌推荐货架期为6～9 d,经巴氏杀菌推荐货架期为6～8 d。     

Effects of High-Intensity Pulsed Electric Fields on Lipoxygenase and Hydroperoxide Lyase Activities in Tomato Juice

ABSTRACT:  The influence of high-intensity pulsed electric field (HIPEF) parameters, namely, pulse frequency, pulse width, and polarity on tomato juice lipoxygenase (LOX) and hydroperoxide lyase (HPL) activities was studied using a response surface methodology. Samples were subjected to square-shaped pulses of 35 kV/cm for 1000 μs, with pulse width ranging from 1 to 7 μs at frequencies from 50 to 250 Hz, either in monopolar or bipolar mode. Tomato LOX was more resistant to HIPEF than HPL within the range of assayed conditions. An increase in frequency or pulse width resulted in a decrease of both residual LOX ( RA_LOX ) and HPL ( RA_HPL ) activities. The lowest  RA_LOX  (81%) was observed when tomato juice was treated at 250 Hz for 7 μs in bipolar mode. Moreover, the same conditions led to the highest HPL activity reduction ( RA_HPL  = 10%). A validation of the predictive models determined that 2nd-order expressions were accurate enough to fit the experimental results.     

Increase of Antioxidant Activity of Tomato Juice Upon Functionalisation with Vegetable Byproduct Extracts

Phenolic-enriched extracts from blanched artichoke (BA), artichoke blanching waters (ABW), cauliflower (CA), carrot (CR), celery (CE) and onion (ON) byproducts were used to ‘functionalise’ tomato juice. The antioxidant activity of functional tomato juice significantly increased over control juice according to a set of in vitro antioxidant assays (i.e. inhibition of lipid peroxidation determined by the ferric thiocyanate method and scavenging of both ABTS^•+ and DPPH^• free radicals). A trained sensory evaluation panel determined the maximal allowed byproduct extract concentration in the functionalisation of tomato juice without modifying its natural sensory properties (mg extract/mL tomato juice): 2.5, 5, 10, 10, 10 and 20 for CA, ON, BA, ABW, CE and CR, respectively. The maximum antioxidant activity (within consumers' acceptance limits and measured by the ABTS^•+ method) was increased 5.4-, 3.4-, 2.5-, 1.7-, 1.5- and 0.6-fold over the control when functional tomato juice was assayed after modification with ABW, BA, CR, ON, CE and CA, respectively. A serving of functional tomato juice (250 mL) containing vegetable extracts (within consumers' acceptance limits) provides an additional intake of phenolic compounds which can range from 22 mg (when functionalised with CA extract) to 300 mg (with BA extract). In the light of the above investigations, the use of vegetable byproducts could be useful for developing a functional tomato juice with potentially increased health-promoting properties.     

超高压番茄汁杀菌条件的优化研究

本研究通过响应面法(RSM)建立了超高压杀灭番茄汁中枯草芽孢杆菌(B.subtilis)AS1.1380的二次多项数学模型,验证了模型的有效性。同时利用模型的响应面及其等高线对影响超高压杀菌的关键因子温度、压力和保压时间及其相互作用进行了深入的探讨。优化出杀灭番茄汁中6个数量级枯草芽孢杆菌AS1.1380的工艺参数为:温度33.5℃,压力469.2MPa,时间14.0min。     

贮藏时间对超高压处理鲜榨番茄汁品质的影响

以热处理(100℃处理5 min)作为对照,评价超高压处理(25℃和400 MPa处理30 min)鲜榨番茄汁贮藏3个月期间的品质和风味变化规律。结果显示超高压处理的鲜榨番茄汁在2个月的贮藏期内,菌落总数、霉菌和酵母菌数量均在国家食品卫生标准以内;pH值、PPO和POD活性逐渐降低;维生素C含量降低约24%,而热处理的鲜榨番茄汁中维生素C含量降低约96%;超高压处理的鲜榨番茄汁风味更加接近于番茄的原有香气,而热处理引起风味的显著性变化。因此,超高压处理的鲜榨番茄汁在2个月的贮藏期内品质和风味均优于传统热处理番茄汁。