Evaluation of heat and oxidative damage during storage of processed tomato products. I. Study of heat damage indices

The evolution of heat damage during storage of tomato pulp, puree and paste was studied by accelerated aging tests. Heat damage indices—5‐hydroxymethyl‐2‐furfural (HMF), furosine and colour changes (ΔE)—were evaluated for tomato products stored at 30, 40 and 50 °C for up to 90 days. Furosine and ΔE values increased following pseudo‐zero‐order kinetics, and the higher the solid content of the products, the higher were the rate constant values. HMF formation followed pseudo‐first‐order kinetics in tomato pulp and pseudo‐zero‐order kinetics in puree and paste samples. Data show that heat damage reactions in tomato products proceed even at room temperature, and the kinetic model provided can be used to predict changes occurring during shelf‐life. © 2002 Society of Chemical Industry     

Variation in antioxidant components of tomato during vine and post-harvest ripening

The variation in the antioxidant content (lycopene, β-carotene, ascorbic acid and total phenolics) was evaluated on two tomato genotypes during vine and post-harvest ripening. Tomatoes were sampled and analysed at seven ripening stages according to the colour value. The data indicate that ripening conditions affected both the antioxidant accumulation kinetics and the final content, which was higher in post-harvest-ripened fruits. In particular, lycopene mainly accumulated in the very last period of ripening and its content was not linearly related to colour changes. Antioxidant accumulation and other ripening indexes were not significantly different in the two tomato genotypes. © 1999 Society of Chemical Industry     

Effects of industrial tomato paste processing on ascorbic acid, flavonoids and carotenoids and their stability over one-year storage

BACKGROUND : The effects of industrial tomato paste processing and long‐term (12 months) ambient storage on the content and stability of quercetin, kaempferol, ascorbic acid (AA), dehydroascorbic acid (DHAA), β‐carotene and lycopene were evaluated in a commercially produced tomato paste. RESULTS : The initial thermal treatment (hot break; 93 °C for 5 min) resulted in significant reductions in quercetin (54%), kaempferol (61%), AA (63%) and β‐carotene (30%), whereas subsequent processing steps (e.g. evaporation and sterilization) did not result in marked changes in these compounds. Lycopene was stable during hot break but decreased by 20% through evaporation and sterilization. The ratio of DHAA:vitamin C increased during hot break to 23%, whereas the ratio of DHAA:vitamin C remained relatively low in subsequent processing steps, indicating that AA was not oxidized. AA decreased with prolonged storage, with only 13% remaining at 12 months. The carotenoids and quercetin remained stable through 12 months of ambient storage. CONCLUSIONS : Tomato pomace contained significant amounts of carotenoids and flavonoids, indicating that it may be an underutilized processing byproduct. Copyright © 2011 Society of Chemical Industry     

减压贮藏对番茄果实抗氧化物质和抗氧化酶的影响

为了研究不同减压处理对番茄果实后熟过程中抗氧化性的影响,以粉冠番茄为材料,研究了在43.6、73.0kPa和常压三个压力条件下,番茄中维生素C、番茄红素和谷胱甘肽含量,以及超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性变化规律。结果表明,减压贮藏显著推迟了番茄中维生素C含量的高峰,在一定程度上延迟了番茄红素和谷胱甘肽含量的高峰,并且压力越低效果越显著(p<0.05);在果实后熟过程中SOD、CAT活性逐渐下降,而减压处理可显著抑制SOD活性下降(p<0.05)。POD活性在贮藏期间呈现先降后升的趋势,减压处理可以有效地保持较高的抗氧化酶活性。结论:减压处理贮藏可以显著保护番茄果实中的抗氧化物质和抗氧化酶活性,而且一定范围内压力越低效果越好。      

Total Phenolics,Carotenoids, Ascorbic Acid,and Antioxidant Properties of Fresh‐cut Mango (Mangifera indica L., cv. Tommy Atkin) as Affected by Infrared Heat Treatment

Abstract: Mango (Mangifera indica L.) is a major tropical fruit that has not been exploited for fresh‐cut or minimally processed products on a scale similar to apples, pineapples, or melons. The objective of this study was to investigate the effect of infrared (IR) treatment on total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh‐cut cubes from ‘Tommy Atkin’ mangoes. Mango cubes were IR treated (5, 10, 15 min) and evaluated at 4‐d intervals during 16‐d storage at 4 ± 1 °C. Total phenolics, carotenoids, and ascorbic acid content in fresh‐cut control mango cubes were 43.33, 1.37, and 15.97 mg/100 g FW, respectively. IR treatments increased total phenolics (59.23 to 71.16 mg/100 g FW) and decreased ascorbic acid (12.14 to 15.38 mg/100 g, FW). Total carotenoids showed a mixed trend (1.13 to 1.66 mg/100 g, FW). The IR treatment showed a significant positive impact on antioxidant properties (μM TE/100 g, FW) of mango cubes, as assayed by ABTS (261.5 compared with 338.0 to 416.4), DPPH (270.5 compared with 289.4 to 360.5), and ORAC (6686 compared with 8450 to 12230). Total phenolics, carotenoids, ascorbic acid, and antioxidant capacity decreased over 16‐d storage. However, IR treated samples had consistently higher ABTS, DPPH, and total phenolics during storage. It was demonstrated that IR treatment can be effectively used in improving antioxidant properties of fresh‐cut mangoes with minimal effect on the visual appearance. Practical Application: Various methods/treatments are in use for extending the quality of fresh‐cut fruits, including mild heat treatment. This study explored the application of infrared (IR) heat for processing fresh‐cut mango cubes and evaluated its effect on vitamin C and antioxidant capacity during 16‐d storage. This is the first study reporting on the use of IR heat in fresh‐cut fruits. IR treatment was shown to be effective in retaining antioxidant properties of fresh‐cut mango cubes with minimal effect on the visual appearance.     

Evaluation of antioxidant activities of rosehip ethanol extracts in different test systems

Rosehip extracts of 18 samples representing six taxa in the genus Rosa were evaluated for antioxidant activities by use of different test systems. The ferric‐reducing antioxidant power (FRAP) and Trolox‐equivalent antioxidant capacity (TEAC) of the crude extracts ranged from 983.4 to 2187.1 µmol FRAP g⁻¹ dry matter and from 457.2 to 626.2 µmol TEAC g⁻¹ dry matter. The high antioxidant capacity was related to high contents of phytonutrients. The overall mean of antioxidants was 23.23 mg g⁻¹ total carotenoids and 76.26 mg g⁻¹ total phenolics. The phenolic component made a major contribution to the total antioxidant activities in both assays (overall mean was 90.5% and 75.7%), whereas the ascorbate made a minor contribution (8.6% and 16.9%) and the lipophilic component made an even smaller one (0.9% and 7.3%). However, the lipophilic component was the most effective when the comparison was based on the ratio of antioxidant activity to content of antioxidants. The crude extracts exhibited 50.9% (46.6–60.3%) inhibitory effect against the lipid peroxidation induced by 2,2′‐azobis(2,4‐dimethylvaleronitrile) (AMVN) and 85.0% (80.1–90.2%) inhibition in 2,2′‐azobis(2‐amidinopropane)hydrochloride (AAPH) assay at a concentration of 250 µg ml ⁻¹. Ascorbate acted as an antioxidant in both peroxy radical‐induced lipid peroxidations, but as a pro‐oxidant in the metal ion‐induced lipid peroxidation. The crude extracts showed a large inhibitory effect in the ferric ion‐induced lipid peroxidation and caused 83.7% inhibition at a concentration of 25 µg ml ⁻¹ dried rosehip powder. © 2000 Society of Chemical Industry     

不同品种梨果实贮藏期间抗氧化活性及品质分析

为探明不同品种梨果实贮藏期间抗氧化活性和品质指标的变化,以康佛伦斯、凯斯凯德、黄金、圆黄、京白和鸭梨为试材,研究了6个不同品种梨在采收时和贮藏后的总抗氧化能力、自由基清除能力、抗氧化物质含量以及品质指标。结果表明,西洋梨的抗氧化性最强,其中康佛伦斯强于凯斯凯德,日韩梨和中国梨次之。西洋梨的硬度、可溶性固形物和还原糖含量也较高。贮藏过程中,各品种梨的抗氧化活性呈现先下降后上升的趋势,抗氧化物质中维生素C的变化最明显,呈显著下降趋势(p<0.05)。各品种梨中康佛伦斯的抗氧化物质含量较高,尤其是总酚含量最高,其硬度和可溶性固形物含量也较高。      

番茄果实采后贮藏的颜色动力学研究

研究了番茄采后成熟过程中果皮颜色的变化规律,建立了多种颜色指标的动力学模型。认为番茄采后成熟过程中色泽角(H0)、色泽比(a/b)、色泽总量(La/b)和a值、明度等颜色参数的动力学变化模型符合一级动力学方程。番茄采后成熟过程中最佳颜色指标是色泽角(H0)。根据实验数据采用数理统计的方法分别确定了各颜色模型的参数：参考变化速率常数(Kref)和反应活化能(Ea)。     

Organically grown tomato (Lycopersicon esculentum Mill.): bioactive compounds in the fruit and infection with Phytophthora infestans

BACKGROUND: Tomato fruits are characterized by a good nutritional profile, including different bioactive compounds such as carotenoids, phenolic compounds and ascorbic acid. The objective of this study was to analyze the content of bioactive compounds in the fruit and the infection by Phytophthora infestans of 28 tomato genotypes from organic outdoor production. The relationship between bioactive compounds in the fruit and infection with P. infestans was estimated. Field experiments were carried out in 2004 and 2005 at two locations in central Germany. RESULTS: Significant variation among genotypes, locations and years was observed for the content of lycopene, ascorbic acid, total phenolic compounds, antioxidant capacity and the infection level of P. infestans. Antioxidant capacity seemed to be influenced mainly by the phenolics and was highest in small fruits, which were less infected with P. infestans. CONCLUSION: The large genetic variation among tomato genotypes for the content of bioactive compounds in their fruit allows for selection gains. None of the investigated bioactive compounds can be recommended for the indirect selection for increased field resistance against P. infestans. Copyright © 2011 Society of Chemical Industry     

即食鱼糜制品贮藏过程中的品质稳定性研究

为了确定即食鱼糜制品在贮藏过程中的品质稳定性,本文研究了120℃高温杀菌的鱼糜制品在不同温度下贮藏的品质变化。样品分为两组,分别在4℃和30℃下进行贮藏,每隔一段时间后测定其破断力、破断距离、质构、持水力、白度、扫描电镜和脂肪氧化等指标,探究鱼糜制品的品质在贮藏过程中的变化。实验发现,随着贮藏时间的延长,鱼糜制品的硬度、破断力略微上升,但是弹性、内聚性和破断距离等指标没有显著变化,持水力随着贮藏时间的增大而减少。白度值在4℃贮藏过程中略微增大,但在30℃时相对平缓。从微观结构来看,鱼糜制品的三维网络凝胶结构发生了一定的改变,纤维骨架变细且断裂成小段,4℃时的网络结构较30℃相对有序和稳定。硫代巴比妥酸值(TBA)和挥发性盐基氮(TVBN)随贮藏时间的变化都呈现上升趋势,4℃下的增长比较平缓,脂肪氧化和产品腐败程度轻微。因此,低温贮藏过程中,鱼糜制品的品质趋于稳定,能有效延长货架期。      

Cholesterol oxide, cholesterol, total lipid and fatty acid contents in processed meat products during storage

The effects of storage time on the formation of cholesterol oxides and on alterations in the fatty acid composition of processed meat products manufactured by Brazilian industries were investigated in this study. Cholesterol oxides and cholesterol were determined by HPLC using photodiode array and refractive index detectors. Samples of jerked beef, Italian-type salami, chicken mortadella and Chester mortadella were analysed at 30 day intervals starting at zero time, for 90 days for the mortadella and 120 days for the jerked beef and salami. The mortadellas were stored under refrigeration at 6 °C and the jerked beef and salami at room temperature, but protected from the light. No cholesterol oxides were formed during the storage time in any of the samples. The cholesterol content, the fatty acid composition and total lipid contents showed no significant differences during storage with the exception of the total lipid content of the jerked beef, which varied from 3.5 at zero time to 2.4 g/100 g after 120 days storage.     

不同烹饪加工豇豆在冷藏过程中亚硝酸盐含量及抗氧化性能的变化

研究了水煮、蒸和油炸3种烹饪加工豇豆在4℃冷藏过程中亚硝酸盐含量及抗氧化性能的变化。采用福林酚法和TEAC法分别测定了不同烹饪加工豇豆提取物的多酚含量和抗氧化能力。结果表明:烹饪加工豇豆的亚硝酸盐含量显著高于新鲜豇豆;在冷藏过程中亚硝酸盐含量均先升后降,在贮藏第3天时,含量最高。在整个贮藏过程中,水煮豇豆的亚硝酸盐含量均显著高于其他组的。豇豆经烹饪加工后,其游离酚含量显著下降,其中油炸豇豆下降最显著,蒸豇豆下降最少。经蒸和油炸后豇豆的结合酚含量显著增加,其中油炸后增加的量更多,而水煮后结合酚含量则显著下降。随着贮藏时间的延长,不同烹饪加工豇豆的游离酚含量均显示出先增加后下降的趋势,而结合酚含量则显著下降。总抗氧化能力与多酚含量变化趋势比较相似,它们之间存在高度相关性。     

Phytochemicals and quality characteristics of candied paprika (Capsicum annuum L.) during storage

In this study, we prepared candied paprika from various coloured fresh paprika and compared the changes in phytochemicals and quality for 42 days by analysing carotenoids, ascorbic acids and total phenolic content, and by assessing sensory and instrumental qualities. We identified five types of carotenoids from candied red paprika (CRP) and three from candied orange paprika (COP) and candied yellow paprika (CYP). At 0‐day storage, capsanthin and β‐carotene in CRP were quantitatively analysed to 26.96 μg g^?1 fw and 3.81 μg g^?1 fw, zeaxanthin and β‐carotene in COP were 9.35 μg g^?1 fw and 4.16 μg g^?1 fw, and lutein and β‐carotene in CYP were 0.27 μg 100 g^?1 fw and 0.70 μg 100 g^?1 fw, respectively. After 42‐days storage, CRP retained approximately 68.6% carotenoids, COP retained 40%, and CYP retained 33%. Ascorbic acid and total phenolic content decreased during storage as carotenoids did. However, rates of decrease were different in different coloured paprika, especially, ascorbic acid in COP and phenolic acid in CRP were considerably conserved for 42 days. Hardness, springiness and chewiness in all samples were significantly increased by 14‐days storage and maintained until 42‐days storage, and all the sensory parameters, including colour, appearance, odour, texture, paprika flavour and overall consumer preference showed no differences until 28 days.     

Quality parameters and antioxidant properties in organic and conventionally grown broccoli after pre‐storage hot water treatment

BACKGROUND: Demand for broccoli has increased due to its high content of bioactive compounds. However, broccoli is a perishable commodity with a short shelf life mainly due to dehydration, yellowing and losses of bioactive compounds. Thus, efficient treatments to preserve broccoli quality are needed. RESULTS: The effect of heat treatment on senescence and antioxidant compounds evolution during storage at 20 °C was evaluated in organic and conventionally grown broccoli. Senescence evolved quickly as manifested by floral head yellowing, which was higher in conventional than in organic broccolis, but senescence was significantly delayed by heat treatment. All organic acids, including ascorbic acid, were found at higher concentrations in organic than in conventional broccoli at harvest but decreased during storage in all broccolis. Phenolic concentration and antioxidant activity (in both hydrophilic and lipophilic fractions) also decreased during storage, although these decreases were higher in conventional than in organic broccolis, and no differences were found attributable to heat treatment. CONCLUSIONS: Heat treatment was effective in delaying broccoli senescence, manifested by chlorophyll retention. In addition, organic broccoli maintained higher concentrations of bioactive compounds (ascorbic acid and phenolics) and antioxidant potential during storage than conventional broccoli, with higher potential health beneficial effects. © 2012 Society of Chemical Industry     

Keeping quality of tomato fruit by high electrostatic field pretreatment during storage

BACKGROUND: High electrostatic field, as a feasible and non‐chemical technique, applied to food preservation is a new area of study. The present article intensively investigated this new preservation method, together with its effects on post‐harvest physiology and quality of tomato. RESULTS: Green mature tomatoes were exposed to negative (or positive) high electrostatic field for 2 h at 20 °C and then stored for 30 days at 13 ± 1 °C, 85–90% RH. Our results indicated that negative high electrostatic field (?2 kV cm^?1) could delay the decline of firmness and the change in color, total soluble sugar and titratable acidity of tomato fruit during storage. The peak of respiration and ethylene production of tomato fruit during storage were delayed by negative high electrostatic field treatment for 6 days and 3 days, respectively. Increases of malondialdehyde content and electrical conductivity in tomato fruit were inhibited significantly by negative high electrostatic field treatment during storage (P < 0.05). CONCLUSION: A high electrostatic field of ? 2 kV cm^?1 can be used to keep the qualities and extend the shelf‐life of tomato fruit. Further research should be highly recommended to understand the mechanisms improving the storability of tomato fruit by negative high electrostatic field. Copyright © 2007 Society of Chemical Industry     

Changes of bioactive compounds and anti‐oxidant activity during cold storage of carrots

Carotenoids, total phenolics and anti‐oxidant activity of carrots were determined during 6 months of storage at 0 °C, 85–90% relative humidity. In addition to changes in CIE colour parameters (L*, a*, b*, h and C), physicochemical properties of carrots including water soluble solids; pH and titratable acidity were evaluated. Cold storage of carrots did not affect the carotenoid levels (β‐carotene, α‐carotene and total carotenoid) except lutein, which showed a 37.5% loss. Total phenolic concentration of carrots decreased significantly (P < 0.05) over the entire storage period. The anti‐oxidant activity of carrots decreased with a level of 31% and was found correlated with total phenolics and lutein content in carrots. While CIE L* and a* parameters decreased significantly (P < 0.05) after 6 months of storage, the b* and C parameters were statistically unchanged for the first 4 months of storage, but decreased gradually for the following period.