番茄籽油精炼过程中番茄红素含量变化的研究

以番茄籽压榨油为原料,采用分光光度法测定番茄籽油中番茄红素在精炼过程中的含量变化。结果表明,番茄红素在精炼各工序均有损失,且脱色>碱炼>水洗>脱臭,碱炼和脱色过程损失分别为17.88%和75.39%。碱炼过程,当碱液浓度升高(8.5%~11.5%),油中番茄红素残留量会降低。脱色过程,增加白土用量或升高脱色温度,油中番茄红素残留量都会减少,当白土用量为2%、脱色温度为100℃时,番茄红素脱除率最高;脱色5min后油中番茄红素残留量无明显变化。      

Effect of thermal processing on the degradation, isomerization, and bioaccessibility of lycopene in tomato pulp

Thermal processing affects the nutritional value of food products. The nutritional value is not only determined by the content but also by the bioaccessibility of nutrients. The present study was performed to gain detailed insight into the influence of thermal processing on the degradation, isomerization, and bioaccessibility of lycopene isomers in tomato pulp, without adding any other ingredient. The bioaccessibility, which is defined as the fraction of the nutrient that can be released from the food matrix, was measured using an in vitro method. The results demonstrated the rather high thermal stability of lycopene. Although a treatment at 140 °C induced isomerization, the contribution of cis-lycopene to the total lycopene content remained small. Results also confirmed that thermal processing as such can improve the in vitro bioaccessibility of lycopene in tomato pulp, but the improvement was only significant upon treatments at temperatures of 130 and 140 °C. At such intense process conditions, one should be aware of the negative effect on other quality and nutrient parameters. Possibilities of thermal processing as such to improve the nutritional value of tomato pulp (without the addition of other ingredients) thus looks rather limited.     

番茄红素的提取及其在大豆油中稳定性、抗氧化性的研究

用有机溶剂从番茄原料中提取番茄红素油树脂,采用皂化法与重结晶相结合的方法来纯化番茄红素油树脂得到番茄红素晶体。考察了时间、温度、光照对溶于大豆油中的番茄红素稳定性的影响;并对不同添加量番茄红素对大豆油的抗氧化性进行了实验。结果表明,番茄红素在大豆油中的保存率随着贮存时间的延长而降低,低温避光贮存比高温光照贮存的保存率高。高添加量番茄红素对大豆油的抗氧化效果显著。     

Effects of genotype and cultivation environment on lycopene content in red‐ripe tomatoes

Lycopene, a natural red pigment found in tomato, is correlated with reduced incidence of some cancers. Forty tomato varieties, including cluster F₁ hybrid tomatoes, round breeding line tomatoes (Lycopersicon esculentum Mill) and cherry tomato types (L esculentum var cerasiforme), grown under greenhouse and field conditions were evaluated for their lycopene content using high‐performance liquid chromatography (HPLC) and spectrophotometry. Lycopene content varied significantly among the tomato varieties, with cherry tomato types having the highest lycopene content. Greenhouse‐grown cluster and round tomatoes contained more lycopene (mean = 30.3 mg kg^?1) than field‐grown tomatoes (mean = 25.2 mg kg^?1), whereas cherry tomato types had a higher lycopene content in field‐grown (mean = 91.9 mg kg^?1) than in greenhouse‐grown (mean = 56.1 mg kg^?1) fruits. HPLC analysis of lycopene isomeric forms revealed a higher content of all‐trans isomers in all tomato genotypes examined. However, the cis isomeric form was exceptionally higher in the field‐ and greenhouse‐grown cherry tomato L esculentum var cerasiforme cv Gardener's Delight, which contained ～9.3 and 9.9 mg kg^?1 cis isomers respectively. Results indicate that genetics and choice of cultivation environment may have a strong influence on tomato lycopene content. Copyright © 2005 Society of Chemical Industry     

Effect of extraction conditions on lycopene extractions from tomato processing waste skin using response surface methodology

Skin, rich in lycopene, is an important component of waste originating from tomato paste manufacturing plants. A central composite design with five independent variables, namely solvent/meal ratio (20:1, 30:1, 40:1, 50:1, and 60:1 v/w); number of extractions (1, 2, 3, 4 and 5); temperature (20, 30, 40, 50 and 60 °C); particle size (0.05, 0.15, 0.25, 0.35 and 0.43 mm); extraction time (4, 8, 12, 16 and 20 min) was used to study their effects on lycopene extraction. The experimental values of lycopene ranged between 0.639 and 1.98 mg/100 g. The second order model obtained for extracted lycopene revealed a coefficient of determination (R²) of 0.99 and a standard error of 0.03. Maximum lycopene (1.98 mg/100 g) was extracted when the solvent/meal ratio, number of extractions, temperature, particle size and extraction time were 30:1 v/w, 4, 50 °C, 0.15 mm and 8 min, respectively.     

Processing of tomato: impact on in vitro bioaccessibility of lycopene and textural properties

BACKGROUND: Human studies have demonstrated that processing of tomato can greatly increase lycopene bioavailability. However, the difference between processing methods is not widely investigated. In the current study different thermal treatments of tomato were evaluated with regard to their impact on in vitro bioaccessibility and retention of lycopene and β‐carotene as well as textural properties. Thermal treatments used were low (60 °C) and high (90 °C) temperature blanching followed by boiling. RESULTS: Lycopene was relatively stable during thermal treatment, whereas β‐carotene was significantly (P < 0.05) reduced by all heat treatments except for low temperature blanching. In vitro bioaccessibility of lycopene was significantly increased from 5.1 ± 0.2 to 9.2 ± 1.8 and 9.7 ± 0.6 mg kg^?1 for low and high temperature blanching, respectively. An additional boiling step after blanching did not further improve lycopene bioaccessibility for any treatment, but significantly reduced the consistency of low temperature treated samples. CONCLUSION: Choice and order of processing treatments can have a large impact on both lycopene bioavailability and texture of tomato products. Further investigations are needed, but this study provides one of the first steps towards tomato products tailored to optimise nutritional benefits. Copyright © 2010 Society of Chemical Industry     

亚临界水提取油棕果渣多酚响应面优化研究

目的为了更好地利用农副产品,回收利用农业废弃物中的有效成分,以油棕果脱壳提油后的废弃物——油棕果渣为原料,以亚临界水技术萃取果渣中酚类物质。方法通过单因素实验对料液比、时间、温度等工艺参数进行研究,并用响应面Box-Behnken试验设计对提取工艺进行优化,建立二次多项数学模型。结果最终通过验证得到亚临界水萃取油棕果渣多酚类物质的最优的工艺条件:液料比50 m L/g,时间40 min,温度250℃。实际测得多酚含量为6.26 g/100 g,与理论值相符合。结论本研究对生产实际具有良好的参考指导作用。     

Extraction of pure lycopene from industrial tomato by‐products in water using a new high‐pressure process

BACKGROUND: Lycopene, a precursor of β‐carotene with a well‐known antioxidant activity, contained in many natural products such as tomato (Lycopersicon esculentum Mill.), watermelon, red pepper and papaya, is usually recovered from natural vegetal sources using organic solvents and a purification step. In this paper an innovative process for the extraction of pure lycopene from tomato waste in water that uses the Naviglio^® extractor and water as extracting phase is presented. RESULTS: Lycopene was obtained in the all‐trans form at a very high grade of purity, not less than 98% (w/w), with an average recovery of 14% (w/w). The availability of high‐purity trans‐lycopene allowed measurement of the molar absorption coefficient. An alternative procedure for high‐performance liquid chromatographic analysis using a phenyl‐hexyl silicone phase as inverse phase and a linear gradient in water and acetonitrile is also described. CONCLUSIONS: The use of water as extracting phase considerably reduces the cost of the entire process when compared with the commonly used solvent‐based procedure or with the newer supercritical extraction process of lycopene from tomato waste. Lycopene, not soluble in water, was recovered in a quasi‐crystalline solid form and purified by solid‐phase extraction using a small amount of organic solvent. Copyright © 2008 Society of Chemical Industry This article was published online on September 15, 2008. Errors in Figures 2 ‐ 4 were subsequently identified. The publishers wish to apologise for these errors. This notice is included in the online and print versions to indicate that both have been corrected [September 19, 2008]     

响应面法优化超声乳化制备油茶籽油纳米乳液及其稳定性研究

以Tween80为乳化剂,研究了超声功率、油茶籽油体积分数、乳油比及其交互作用对超声乳化制备油茶籽油纳米乳液平均粒径及多分散指数的影响,利用响应面法优化了制备条件并对油茶籽油纳米乳液的稳定性进行初步评价。结果表明:油茶籽油纳米乳液的平均粒径及多分散指数模型拟合度R~2分别为0.974 2和0.951 9;最优制备条件为超声功率405 W、超声时间15 min、油茶籽油体积分数8.3%、乳油比0.16∶1,在该条件下油茶籽油纳米乳液的平均粒径为(74.9±0.85)nm,多分散指数为0.17±0.01;贮存温度、贮存时间及二者的交互作用对油茶籽油纳米乳液的平均粒径及多分散指数有极显著影响(P0.01),油茶籽油纳米乳液在5℃和25℃条件下贮存60 d,其平均粒径小于90 nm,多分散指数小于0.3,表现出了较好的动力学稳定性。     

Effect of increasing manganese concentration in nutrient solution on the antioxidant activity,vitamin C,lycopene and polyphenol contents of tomato fruit

ABSTRACT

This study evaluated the effect of increasing manganese (Mn) nutrition on the content of antioxidative compounds such as vitamin C, lycopene and polyphenols, and the antioxidant activity of tomato (Lycopersicon esculentum Mill., cvs ‘Alboney F1’ and ‘Emotion F₁’) fruit. Plants were grown in rockwool using a nutrient solution with the following content of Mn (mg dm^–3): 0.0, 0.3, 0.6, 1.2, 2.4, 4.8, 9.6 and 19.2. The level of vitamin C and lycopene decreased with the increasing Mn nutrition. Since the colour of fruits was correlated with the change in carotenoid content, the decrease in lycopene content promoted the reduction of redness and increase of yellowness of fruits. However, total polyphenol content and antioxidant activity significantly increased when plant were exposed to toxic levels of Mn. Observed changes could be the result of the oxidative stress induced by high concentrations of Mn. Polyphenolic compounds play a crucial role in the plant’s response to Mn stress and affect predominantly the total antioxidant properties of fruits, which could be used as a source of phenolics. Moreover, total phenolic content measurement, as an easy and inexpensive method, could be used as an indicator of Mn-induced stress in fruits of tomato.     

Impact of lemon oil composition on formation and stability of model food and beverage emulsions

Lemon oil is a complex organic compound isolated from citrus peel, which is commonly used as a flavouring agent in beverages, foods, cosmetics, and household products. We have studied the influence of lemon oil fold (1×, 3×, 5× and 10×) on the formation and properties of oil-in-water emulsions. Initially, the composition, molecular characteristics, and physicochemical properties of the four lemon oils were established. The main constituents in single-fold lemon oil were monoterpenes (>90%), whereas the major constituents in 10-fold lemon oil were monoterpenes (≈35%), sesquiterpenes (≈14%) and oxygenates (≈33%). The density, interfacial tension, viscosity, and refractive index of the lemon oils increased as the oil fold increased (i.e., 1× < 3× < 5× < 10×). The stability of oil-in-water emulsions produced by high pressure homogenisation was strongly influenced by lemon oil fold. The lower fold oils were highly unstable to droplet growth during storage (1×, 3×, and 5×) with the growth rate increasing with increasing storage temperature and decreasing oil fold. Droplet growth was attributed to Ostwald ripening, i.e., diffusion of lemon oil molecules from small to large droplets. The highest fold oil (10×) was stable to droplet growth, which was attributed to the presence of an appreciable fraction of constituents with very low water-solubility that inhibited droplet growth through a compositional ripening effect. This study provides important information about the relationship between lemon oil composition and its performance in emulsions suitable for use in food and beverage products.     

罗茨水环真空机组在米糠油物理精炼中的应用

罗茨水环真空机组用于米糠油物理精炼,运转功率小,维护费用低,安装灵活方便,降低了生产成本,取得了良好的经济效益。生产出的成品油,达到国标四级精炼米糠油要求。此机组适合在小规模物理精炼生产线中应用。     

热处理对纺织品拒水拒油功能的回复作用

经含氟整理剂处理的纺织品在经过汗渍、摩擦、沾污、皂洗、氯漂等外界因素影响后,其拒水拒油性能均有一定程度下降,而经过150℃的高温焙烘后,其拒水拒油性又可得到一定程度的回复。通过应用EDS分析技术,测定了含氟整理织物、20次水洗后织物和经过再次高温焙烘处理后织物的表面氟含量,进一步揭示了纺织品拒水拒油功能削弱和回复的主要原因是氟原子在纤维/织物表面的定向排列发生了改变。     

Low-fat meat sausages with fish oil: Optimization of milk proteins and carrageenan contents using response surface methodology

Response surface methodology was used to analyze the effect of milk proteins and 2:1 κ:ι-carrageenans on cooking loss (CL), weight lost by centrifugation (WLC) and texture attributes of low-fat meat sausages with pre-emulsified fish oil. A central-composite design was used to develop models for the objective responses. Changes in carrageenans affected more the responses than milk proteins levels. Convenience functions were calculated for CL, WLC, hardness, and springiness of the product. Responses were optimized simultaneously minimizing CL and WLC; ranges for hardness and springiness corresponded to commercial products (20 g of pork fat/100 g). The optimum corresponded to 0.593 g of carrageenans/100 g and 0.320 g of milk proteins and its total lipid content was 6.3 g/100 g. This formulation was prepared and evaluated showing a good agreement between predicted and experimental responses. These additives could produce low-fat meat sausages with pre-emulsified fish oil with good nutritional quality and similar characteristics than traditional ones.     

响应面法优化脉冲电场处理油菜籽的工艺及品质评价

目的 探究脉冲电场(pulsed electric field, PEF)处理油菜籽的提取工艺、理化性质和品质评价。方法采用PEF预处理油菜籽,通过单因素实验考察脉冲电压、停留时间、脉冲频率和脉冲宽度4个因素对菜籽油出油率的影响,并通过响应面法优化其提取工艺;通过扫描电镜、红外光谱、紫外光谱和国家标准方法测定PEF处理菜籽油的理化性质;通过气相色谱-质谱法(gas chromatography-mass spectrometry, GC-MS)测定PEF处理菜籽油的脂肪酸组成。结果 PEF处理菜籽油的最佳提取工艺为:脉冲电压35 kV、停留时间184 s、脉冲频率810 Hz、脉冲宽度8μs,在此条件下油菜籽出油率为93.25%±0.19%; PEF处理能够破坏油菜籽的细胞结构,增加其出油率;经PEF处理的菜籽油具有一般植物油的特征结构;与压榨法相比, PEF处理降低了菜籽油的酸价,减缓了菜籽油的氧化程度,其他品质指标符合国家标准中一般菜籽油的质量要求; PEF处理增加了亚油酸、亚麻酸和棕榈酸的含量,降低了油酸的含量。结论 最佳提取条件下,PEF处理菜籽油的出油率可达93.25%,经P...     

Optimization of supercritical carbon dioxide extraction of sea buckthorn (Hippophaë thamnoides L.) oil using response surface methodology

Response surface methodology (RSM) was employed to optimize the conditions of supercritical CO₂ extraction of the whole berry oil from sea buckthorn. The effects of pressure, temperature, CO₂ flow rate and extraction time on the yield of oil, vitamin E and carotenoids were investigated. Results showed that the data were adequately fitted into three second-order polynomial models. The independent variables, the quadratics of pressure and extraction time, the interactions between pressure and temperature, pressure and extraction time, temperature and extraction time, as well as flow rate and extraction time had a significant effect on the yield of the oil, vitamin E or carotenoids. It was predicted that the optimum extraction conditions within the experimental ranges would be the extraction pressure of 27.6 MPa and temperature of 34.5 °C with flow rate of 17.0 L/h and extraction time of 82.0 min. Under such parameters, the yields of oil, vitamin E and carotenoids were predicted to be 208.0 g/kg, 288.7 mg/kg and 620.0 mg/kg dry sea buckthorn berry, respectively. Monounsaturated fatty acids were predominant in the whole berry oil, accounting for over 62% of the total fatty acids.     

响应面法优化甜瓜籽油的超声辅助提取工艺及其品质分析

为提高甜瓜籽利用率,采用超声辅助提取工艺提取甜瓜籽油,以甜瓜籽油得率及DPPH自由基清除率为指标,通过单因素实验研究超声时间、超声温度、料液比、浸提时间对甜瓜籽油提取的影响,在此基础上采用响应面实验对提取工艺条件进行优化,并测定提取的甜瓜籽油理化指标、总酚含量、甾醇和脂肪酸组成及含量。结果表明：甜瓜籽油的最佳提取工艺条件为浸提时间3 h、料液比1∶7.7、超声温度43℃、超声时间41 min,在此条件下甜瓜籽油得率为25.64%,DPPH自由基清除率为60.66%;制备的甜瓜籽油酸值(KOH)为0.52 mg/g,过氧化值为0.00 mmol/kg,碘值(I)为133.38 g/100 g,总酚含量为8.72 mg/100 g;甜瓜籽油中共检出5种脂肪酸,其中亚油酸含量最高,为66.68%,共检出7种甾醇,总含量达306.10 mg/100 g,其中β-谷甾醇含量最高,为138.60 mg/100 g。甜瓜籽油营养价值较高,可作为食用油进一步开发利用。