不同条件下存放时番茄皮中番茄红素的降解动力学

光照、空气及温度等对番茄皮中番茄红素降解动力学参数的影响表明，温度对反应影响最为显著，番皮原料中番茄红素的含量变化遵从假一级反应规律，其ＬｎＫ－１／Ｔ关系为一条直线。作者计算出了番匣红素在光＋空气、光＋氮气、暗＋空气及暗＋氮气条件下降解反应的活化能分别为９．４５，１０．４６，９．７７及１４．５０ｋＪ／ｍｏｌ。     

Dry fermented sausages enriched with lycopene from tomato peel

Tomato industries yield a high amount of by-products mainly tomato peel and seeds. Since tomato peel is rich in lycopene, the direct addition of peel to food products could be a way to use this by-product to obtain a new products enriched in lycopene. This work describes experiments performed to develop dry fermented sausages (salchichón) containing this carotene. 0%, 0.6%, 0.9% and 1.2% (w/w) of dry tomato peel was added to the meat mixture used in sausage manufacture. A slight losts of lycopene was detected after 21 days ripening, however, levels remained between 0.26 and 0.58 mg of lycopene/100 g of sausage. The sensory and textural properties and overall acceptability of all sausages were good, indicating that tomato peel could be added to dry fermented sausages to produce a meat product enriched in lycopene.     

Enzyme aided extraction of lycopene from tomato tissues

Lycopene is a natural carotenoid pigment and a high value nutraceutical having wide use. The objective of the present work was to obtain a good yield of lycopene from tomato tissues, using cellulase and pectinase enzymes. Various parameters such as concentration of enzymes and time of incubation were optimised, to improve the yield of lycopene from tomatoes. Enzyme aided extraction of lycopene from whole tomatoes under optimised conditions resulted in an increase in the lycopene yield by 132 μg/g (198%) in cellulase treated sample and 108 μg/g (224%) in case of pectinase treated sample. Extraction from tomato peel under optimised conditions showed a remarkable increase in the yield of lycopene by 429 μg/g (107%) and 1104 μg/g (206%), for cellulase and pectinase treated samples, respectively. Likewise, the enzyme aided extraction of lycopene from fruit pulper waste and industrial waste of tomatoes was done to determine the potential for recovering the natural pigment from tomato waste.     

Improved lycopene extraction from tomato peels using cell-wall degrading enzymes

Four commercial enzyme preparations with pectinolytic, cellulolytic and hemicellulolytic activities were tested for their ability to enhance lycopene extraction from tomato peels. Screening experiments were performed at 25 °C by subjecting the peels to a 4-h enzyme incubation followed by 1-h hexane extraction. Peclyve EP and LI were the most efficient, with an almost 20-fold increase in extraction yield. Peclyve LI was used to evaluate the influence of solvent type and enzyme incubation time on lycopene recovery. Hexane, ethyl acetate and the mixture hexane/acetone/ethanol 50:25:25 (v/v) were used as solvents. Under the best extraction conditions (1-h enzyme incubation followed by a 3-h solvent extraction at 40 °C) up to 440 mg of lycopene per 100 g of dry tomato peels were obtained. The percentage recoveries were in the range of 3–30%, for the untreated peels, and 77–98% for the enzymatically treated material.     

Improving the stability of lycopene Z-isomers in isomerised tomato extracts

Tomato-based foods rich in Z-lycopene are potentially more bioavailable and have greater bioefficacy compared to natural tomato products which mainly contain all-E-lycopene. To prepare a stable tomato extract with a high level of Z-lycopene, geometrical isomerisation of lycopene was studied in organic solvents either alone or in the presence of a tomato extract. Interconversion between the isomers was observed in all systems with 13Z-lycopene being the least stable. Heating a tomato extract containing mainly the all-E-isomer in ethyl acetate produced successively 13Z-, 9Z- and 5Z-lycopene. An isomerised tomato oleoresin with a minimal content of the most unstable 13Z-lycopene could be obtained by refluxing tomato oleoresin in ethyl acetate for 1 week. In this isomerised tomato oleoresin, total lycopene and lycopene isomer profiles were shown to remain constant for 1 year at room temperature. Accordingly, this product is a valid source of stable and potentially highly bioavailable lycopene.     

Beef hamburgers enriched in lycopene using dry tomato peel as an ingredient

The direct addition of dry tomato peel (DTP) to hamburgers may be useful both to obtain a new product enriched in lycopene and for providing a use for this by-product from the tomato industry. In this study, different amounts of DTP (0–6.0% w/w) were added to raw and cooked hamburgers, and the effects on the meat’s physico–chemical and sensorial characteristics were studied. The maximum DTP concentration compatible with good sensory acceptability and high lycopene content was determined. Addition of DTP increased the colour parameters a^∗ and b^∗ of raw and cooked hamburgers, and modified all textural properties probably because of the presence of fibre. The hardness values of cooked samples was significantly higher in the batch containing 6% DTP (67.6 N) than in a control batch (50.9 N, p < 0.05). The addition of DTP to 4.5% results in hamburgers with good overall acceptability and a lycopene content of 4.9 mg/100 g of cooked hamburger.     

Effect of water activity on lycopene and flavonoid degradation in dehydrated tomato skins fortified with green tea extract

Tomato by-products (skins) were formulated with a green tea (GT) extract (5 mmol flavanol per mmol of lycopene) and dehydrated to obtain powders with potential added-value as food ingredients. The aims were to evaluate product stability during storage at different water activity (a_w) levels in the range 0.17–0.75, by assessing: (a) lycopene and flavonoid degradation rates, (b) the antiglycoxidative and antioxidant properties, and (c) color variations.     

Effect of osmotic pre-treatment and microwave heating on lycopene degradation and isomerization in cherry tomato

Cherry tomato were dehydrated by a combination of different techniques (osmotic dehydration, convective drying, and microwaves assisted air drying) in order to evaluate the effect of the process variables on the degradation and isomerization of lycopene, as well as on the optical properties. Specifically, the effect of prior osmotic treatment, air drying temperature (40, 55, and 80 °C) and level of microwave energy (0, 1, and 3 W/g) were studied. Obtained results showed that the osmotic pre-treatment limited the isomerization during the later stage of drying, whereas both the loss of total lycopene and the trans–cis isomerization, mainly to the 13-cis form, were favored by an increase in temperature and the microwave power. Furthermore, a positive correlation between the degree of isomerization experienced by the samples during drying and the hue (h*) were obtained. This correlation was reflected in the colour of the sample with predominantly more orange tones and less reddish ones.     

Development of healthy extruded maize snacks; Effects of soybean flour and feed moisture content

The main aim of this research was to introduce a green and clean method of increasing the nutritional quality while preserving the quality of extruded maize snacks. This was achieved by addition of soybean flour (5%, 10%, 15% and 20%, w/w) as a source of plant protein, fibre and bioactive compounds and changing the feed moisture content. Extruded samples were produced using a single-screw extruder. Increasing the soybean flour and feed moisture content resulted in reduced specific mechanical energy of the extruder and consequently several changes in physicochemical properties of the snacks including higher moisture content, lower expansion and volume, reduced crispiness, reduction in L-and a-values but an increase in b-value and formation of more wrinkly and thicker air bubbles cell walls as observed under scanning electron microscope. The addition of <20% soybean flour and feed moisture content resulted in snacks with improved nutritional value and physical properties.     

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.     

Antioxidant potential and quality characteristics of Mediterranean fruit‐based extruded snacks

‘Mediterranean snacks’ (dried fruits and nuts as principal ingredients), a little known food product with a high nutritional value, might be considered a good alternative for consumers looking for healthy snacks. The aim of this research was to determine the physicochemical properties and nutritional value of this type of food stuff (traditionally called ‘fruit cakes’ in Mediterranean countries) and to evaluate their phenolic content and antioxidant activity. All the fruit‐based extruded snacks studied are shelf‐stable at room temperature (because of their pH and water activity values). The final product has a low moisture (<32%) and high sugar content (>30%), the only sugars being those naturally present in the food. All the fruit‐based extruded snacks had a dietary fibre content higher than 10% (high‐fibre foods). Date extruded snack and apricot extruded snack showed the highest total phenolic and flavonoid content and also the highest antioxidant activity as determined by the DPPH and FRAP methods.     

Preparative separation and purification of lycopene from tomato skins extracts by macroporous adsorption resins

In order to separate and purify lycopene from tomato skins extracts (lycopene oleoresin) with macroporous adsorption resins (MARs), the adsorption properties of twenty-four kinds of MARs were evaluated. The results showed that LX-68 had higher separation efficiency than other resins. Based on the static experiments with LX-68, it was found that the experimental data fitted best to the pseudo-second-order kinetics model and Langmuir isotherm model. The separation parameters of lycopene from tomato skins extracts were optimised through dynamic adsorption/desorption experiments with the column packed by LX-68. Through only one cycle treatment, the lycopene content in lycopene oleoresin increased 30.4-fold from 0.21% to 6.38%, with a recovery yield of 66.9%, which were determined by HPLC method. The results showed that MARs would provide useful help for the development of large-scale manufacture in the separation of lycopene from tomato skins extracts.     

乙醇酶法从番茄中提取番茄红素的研究

本研究采用乙醇酶法是从番茄中提取番茄红素，研究了酶和乙醇浸取提取方法，并对番茄红素的提取条件作了研究，确定了较佳工艺条件。     

Effect of ultrasound treatments of tomato pulp on microstructure and lycopene in vitro bioaccessibility

The influence of ultrasound treatments of tomato pulp on microstructure and lycopene in vitro bioaccessibility was investigated. To this purpose, samples were subjected to ultrasound at a frequency and amplitude of 24 kHz and 100 μm, respectively, for increasing lengths of time. Results showed that ultrasound was responsible for loss of tomato cell integrity, as well as a decrease in the degree of pectin esterification. In contrast, rheological measurements showed that ultrasonically treated tomato pulp had greater gel-like properties than an untreated sample. It was inferred that ultrasound promoted the formation of a new network due to hydrogen bonding and hydrophobic interactions among the de-esterified pectin molecules. Such a reinforcement of the tomato pulp structure resulted in a decrease in lycopene in vitro bioaccessibility of the ultrasonically treated tomato pulp, probably due to the fact that the presence of a stronger network may make lycopene less available to the digestion process.     

番茄皮中番茄红素提取工艺的研究

主要对番茄皮中番茄红素的提取工艺和影响番茄红素提取的诸因素，如提取溶剂种类及原料与提取溶剂的比例、浸提温度、时间、提取级数等进行了研究，结果表明：选用丙酮为提取溶剂且液料比为8：1，提取温度为40℃，提取时间为70min，提取级数为3次，可取得最佳提取效果。     

Effects of acidification on physico-chemical characteristics of buffalo milk: A comparison with cow’s milk

Composition and physico-chemical properties of buffalo and cow milks were compared at their initial pH and during acidification. As compared to cow milk, buffalo milk was richer in fat, lactose, protein (especially caseins) and minerals such as calcium, magnesium and inorganic phosphate. Along with these differences of major components, the capacity of milk to be acidified (named buffering capacity) was higher for buffalo milk than for cow milk. The precipitation/aggregation of caseins at their isoelectric pH, solubilization of calcium and inorganic phosphate and decrease in hydration of casein as a function of decrease in pH were significant for both milks. For both species, these molecular changes were qualitatively similar but quantitatively different. These quantitative differences during acidification were related to the differences of composition between the milks.     

Effect of extrusion conditions on iron stability and physical and textural properties of corn snacks enriched with soybean ferritin

Soybean sprouts cultured in 20 mm FeSO₄ were introduced into corn snacks (1.75–3.50%) to supplement iron. The effect of extrusion process on the ferritin iron stability and on product quality was studied. Iron stability in these fortified snacks depended mainly on feed moisture levels, with the best results seen when the feed moisture and temperature were 12% and 110 °C, respectively. Lower feed moisture was beneficial to hardness, expansion ratio and bulk density, while lower temperature increased snack hardness and density, while worsening the expansion ratio. The snacks’ water absorption was strongly and directly dependent on the temperature, while their solubility mainly depended inversely on feed moisture. All of the variables tested altered the colour of the snacks. The conditions that were best for producing the ferritin‐fortified snacks – 12% feed moisture, and temperature equal than or less to 140 °C – may yield a product with the desired quality features.     

Production of frankfurters with tomato powder as a natural additive

This study includes the investigation of chemical properties such as nitrosomyoglobin content, lycopene content, and the oxidation level, and the sensorial properties of frankfurters which have been produced by both reducing the nitrite level and adding tomato powder. All samples have been vacuum packed and stored at +4 °C for 60 days.The pH of the frankfurters produced with tomato powder was reduced, when compared to the samples which did not contain tomato powder. This effect was due to the acidic characteristics of tomato. As the level of nitrite was reduced, the oxidation level of the frankfurters was increased significantly. Addition of 2 g/100 g of tomato powder decreased the level of oxidation; however, 4 g/100 g of tomato powder caused a slight increase when compared to the samples which did not contain tomato powder. According to this result it can be stated that tomato powder retards the oxidation reaction. According to sensorial evaluations, tomato powder improved the consumer acceptability as well. Addition of tomato powder increased the internal and external colour scores, and frankfurters were found to be more acceptable by the panellists. Nitrosomyoglobin (NOMb) content of the samples was decreased along with the decreased level of nitrite, and this, in turn, contributed to the decreased level of redness (a*).     

Modelling the stability of lycopene-rich by-products of tomato processing

Tomato by-products were produced by puree manufacturing from heat-stabilised fruits and raw fruits to simulate both conventional and innovative processing technologies. By-products were freeze-dried, ground and stored in five relative humidity environments in the range 11–75%, for 4 months at 30 °C. The aims were: (a) to investigate the effect of heating applied during tomato processing on by-product hygroscopicity and stability, (b) to find out the optimal water activity (a_w) range for by-product stability. Hygroscopicity was studied by applying the Guggenheim–Anderson–de Boer (GAB) model. By-product stability was studied by evaluating the kinetics of lycopene, β-carotene, rutin and chlorogenic acid degradation and the changes in Hunter’s colourimetric parameters during storage.