Antioxidant Bioactive Compounds in Selected Industrial Processing and Fresh Consumption Tomato Cultivars

Four selected fresh consumption tomato varieties, harvested at different ripening stages (green, breaker, pink, red) and five industrial processing tomato varieties, harvested at red ripe stage, were analysed for lycopene and its isomers, β-carotene, total and individual phenolics, vitamin C and hydrophilic antioxidant activity. Tomato variety and ripening stage significantly affected carotenoids, total phenolic compounds and hydrophilic antioxidant activity when fresh consumption tomatoes were compared. The average of total lycopene content at the different ripening stages was 0.63, 12.20, 26.76 and 116.66 mg/kg of fresh weight (FW). Vitamin C ranged from 2.79 (breaker Cherry Pera) to 297.62 (red Cherry Pera) mg/kg FW. In green and breaker tomatoes, a positive correlation of hydrophilic antioxidant activity with vitamin C and chlorogenic acid was observed. However, in industrial tomato varieties (red ripe stage) and fresh consumption varieties harvested at pink and red stages, hydrophilic antioxidant activity was correlated with total phenolics and rutin. Tomato varieties for industrial processing did not show significant differences in total phenolic compounds and lycopene content. Lycopene ranged from 83.17 to 97.60 mg/kg FW, while total phenolic compounds varied between 257.91 and 284.13 mg/kg FW. Chlorogenic acid and rutin were the most abundant individual phenolics found in all the samples studied. Moreover, the content of total phenolics was always significantly correlated with the content of rutin. The amounts of all individual phenolics were affected by variety, with the exception of ferulic acid. Generally, these individual phenolics were more abundant in green and intermediate ripening stages, decreasing in full red tomatoes.     

Physicochemical Changes in Seven Tomato (Lycopersicon esculentum) Cultivars During Ripening

Seven tomato cultivars were studied for compositional changes during ripening at green, breaker, turner, and ripe stages. Result indicated changes in total soluble solids (4.15 to 6.62 g/100 g), acidity (0.36 to 0.54 g/100 g), reducing sugars (0.76 to 4.04 g/100 g), total sugars (1.67 to 5.52 g/100 g), lycopene in skin (0.07 to 14.28 mg/100 g), and in pulp (0.04 to 6.73 mg/100 g) during ripening from green to red ripe stage. Cultivar UC-828 was found superior with respect to total soluble solids (6.62 g/100 g), reducing sugars (4.04 g/100 g), and total sugars (5.52 g/100 g) where as cultivar 8–2–1–2–5 was found superior with respect to lycopene in skin (14.28 mg/100 g) and in pulp (6.73 mg/100 g). Hunter color values showed a change from negative value of ‘a’ (greenness) to positive values (redness) where as ‘b’ decreased. The (b/a) and tan^?1 (b/a) showed a similar pattern of first increased and then decreased. The puncture resistance was decreased from 10.5 to 2.3 N indicating softening during ripening. Correlation studies showed that lycopene content best correlated with Hunter ‘a’ values during ripening (R² = 0.84 to 0.93). Intercultivar variation in physicochemical parameters at all stages of ripening revealed that Castle Rock was the best cultivar.     

Phenolase activity in tomato fruit in relation to growth and to various ripening disorders

An efficient method for the extraction of phenolase from tomato fruit is described. It has indicated that phenolase activity increases towards maturity and then decreases somewhat during normal ripening. The red area of fruit which showed a physiological ripening disorder known as ‘blotch’ contained an abnormally high activity while the green areas contained an even higher activity. Tomatoes exhibiting ‘blossom-end’ rot also contained enhanced activity, especially in the affected region. Levels of phenolase in tomato species other than Lycopersicon esculentum have also been examined. The browning symptoms associated with specific physiological ripening disorders are discussed in relation to phenolase activity and the availability of phenolic substrates.     

Comparative fruit colouration in watermelon and tomato

The characteristic red pigmentation of watermelon and tomato fruits is determined by accumulation of the carotenoid pigment lycopene and this phenotype is polyphyletic. Since several carotenoids are known to have health promoting activity, and watermelon can be a significant source of lycopene and other carotenoids, it is important to understand the genetic basis of watermelon fruit-specific carotenoid biosynthesis. Unlike tomato, very little is known about the regulation of carotenoid biosynthesis during fruit development in watermelon, a non-climacteric fruit. We have HPLC analyzed the carotenoids of red, yellow and orange watermelons and compared their carotenoid patterns with those of known fruit colour mutants of tomato. Interestingly, we could detect tomato mutant equivalents to most watermelon fruit colour phenotypes, including r, og, B and t.     

The non-volatile organic acids of the differently coloured areas of the walls of 'blotchy' ripened tomatoes

A comparative study has been made of the individual non-volatile organic acids in ethanolic extracts of the red and green areas of the walls of tomato fruit showing symptoms of ‘blotchy’ ripening. The titratable and total acidites of the green areas were lower, and the combined acidity higher than those of the red areas. Potassium concentrations in the differently coloured areas did not differ significantly. Concentrations of the dicarboxylic amino-acids, pyrrolidonecarboxylic, malic and citric acids in the green areas were all significantly lower than in the corresponding red areas. Citric acid concentrations were much lower and glutamic acid concentrations higher than those found previously in the walls of uniformly ripened fruit of similar colours. The malic/citric acid ratio in the green areas was approximately double that in the red areas. In both cases values were greater than those normally encountered in evenly ripening fruit. The proportions of the total acidity present as malic acid in the differently coloured areas was strikingly similar to that found in the walls of normally ripened fruit of the same colour and variety. On the other hand the proportion of citric acid was markedly reduced in the ‘blotchy’ fruit walls. It is suggested that low citric acid concentrations combined with the persistence of high polyphenol-oxidase activity may be conducive to ‘blotchy’ ripening of tomato fruit.     

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     

Main quality attributes and antioxidants in Hungarian sour cherries: identification of genotypes with enhanced functional properties

Sour cherry (Prunus cerasus L.) cultivars native to Hungary and some of them grown worldwide, display great phenotypic variability. Eleven sour cherry cultivars were analysed for their main quality attributes including fruit weight, soluble solid content, acidity, pH, specific sugars (glucose and fructose), antioxidant capacity as well as total polyphenolic (TPC), total anthocyanin (TMAC) and vitamin C contents. Results showed wide variation in both fruit quality and antioxidant parameters of Hungarian sour cherries. The anthocyanin contents varied from 11.3 to 93.5 mg/100 g. An amarelle‐type cultivar, ‘Pipacs 1’ showed the highest antioxidant capacity (21.85 mmol AA L^?1), TPC (49.04 mg GA L^?1) and vitamin C (8.98 mg/100 g) content. Key enzymes in anthocyanin biosynthesis were expressed in both yellow‐coloured flesh and red skin of ‘Pipacs 1’ fruits at all ripening stages. The detected diversity presents a choice that can satisfy different consumer preferences, and meet specific nutritional requirements.     

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.     

光质对番茄果实品质及挥发性物质的影响

以‘金棚朝冠’为实验材料,研究植物工厂内不同比例红蓝光（R、2R1B、1R1B、1R2B和B）（白光为对照组）处理对番茄单果质量、主要品质性状及挥发性物质的影响。结果表明：2R1B（红光∶蓝光＝2∶1）处理可以显著提高番茄单果质量以及可溶性蛋白、抗坏血酸和番茄红素的含量,R（红光）处理条件下可溶性固形物含量、可滴定酸质量分数和糖酸比均显著高于白光对照（P＜0.05）。利用顶空固相微萃取结合气相色谱-质谱联用对番茄果实的挥发性物质进行测定,发现与其他比例的红蓝光处理相比较,R和2R1B提高了挥发性物质的总量。本研究结果为利用不同光质提高番茄果实品质和风味提供了理论依据。     

Effects of UV-C,red light and sun light on the carotenoid content and physical qualities of tomatoes during post-harvest storage

Mature-green (breaker-stage) tomatoes were harvested and treated daily with short bursts of UV-C, red light or sun light for up to 21 days. Control untreated tomatoes were kept in the dark for the same period. The effects of the treatments on the levels of the major tomato carotenoids, skin colour, tissue firmness and total soluble refractive solids were evaluated throughout storage. Results indicated that the concentration of lycopene in tomato exocarp was significantly increased after 4 days and dramatically enhanced by UV-C or red light treatments. However, the concentration of β-carotene was not affected by UV-C or red light treatments, and decreased by sun light treatment during 21 days of storage, compared to the control samples. The colour (a∗ and b∗ values) and force required to penetrate the tomatoes was, to a small but significant extent, influenced by the light treatments. However, the total soluble refractive solids of all tomato samples remained the same throughout storage. The findings reported here could be employed to improve tomato nutritional qualities lycopene content without inducing significant changes to the physical properties of tomatoes during post-harvest storage.     

Structural changes,chemical composition and antioxidant activity of cherry tomato fruits (cv. Micro‐Tom) stored under optimal and chilling conditions

BACKGROUND: Cherry tomato fruits cv. Micro‐Tom, a model plant for tomato genetics, were analysed in order to determine the main structural and chemical changes under optimal and chilling storage conditions. The comparison of Micro‐Tom to standard tomato cultivars will give an insight into suitability of this dwarf cultivar as a model for studying the influence of low‐temperature conditions on tomato fruits. RESULTS: During chilling, fruit tissue was progressively destroyed due to the collapse of the deep layers of the pericarp. Chilling lowered the typical tomato kinetics of ripening in sugars (glucose, fructose, sucrose), organic acids (tartaric, malic, citric, ascorbic and succinic) and the antioxidants phenol and lycopene, while carotenoid synthesis seemed to be blocked. Glutathione level was elevated and the activity of ROS scavenging enzymes was altered. Essentially, Micro‐Tom fruits showed a quality evolution that was similar to that described for standard tomato cultivars. CONCLUSION: The cherry tomato cultivar Micro‐Tom could be used as a model for studying the influence of low temperature on biochemical and structural changes taking place during chilling injury conditions. Copyright © 2009 Society of Chemical Industry     

Changes in the contents of carotenoids,phenolic compounds and vitamin C during technical processing and lyophilisation of red and yellow tomatoes

We present the results of the first study on the impact of thermal processing and lyophilisation on three major micronutrient families: carotenoids, total polyphenols and vitamin C in two different tomato cultivars: a red tomato (RT) and a yellow one (YT). Micronutrients were analysed in fresh tomatoes, tomato purée and lyophilised tomatoes. YT contained no lycopene, lower β-carotene, similar vitamin C and higher total polyphenol contents than RT. Processing did not affect the carotenoid content in RT, but significantly lowered β-carotene in YT and also the contents of total polyphenol and vitamin C in both cultivars. Lyophilisation lowered the carotenoid content in RT but not in YT; in contrast, the total polyphenol content was preserved in RT but lowered in YT, and the vitamin C content was not affected in both cultivars. These results provide new data on the effect of thermal processing and lyophilisation on the content of the three main families of micronutrients in red and yellow tomatoes.     

Effects of harvest time on the quality attributes of processed and non‐processed tomato varieties

This study examines physicochemical changes in newly developed and existing tomato varieties at different levels of maturity. Serum viscosity is an important factor in the selection of tomato varieties for processing. Most of the attributes indicative of quality for fresh and paste tomatoes occurred at a less mature stage and declined with maturity. The canned varieties ‘H9888,’‘H8892’ and ‘H9780’ had a greater ascorbic acid content and antioxidant capacity. The highest lycopene contents were found in the varieties ‘H9888,’‘CXD254,’‘CXD222’ and ‘H9780’. Total soluble solids levels increased with maturity. The highest acidity values occurred in canned ‘Shasta’, ‘CXD254’ and ‘H9780’ varieties. Mid‐ and late‐season varieties harvested at an early stage produced thicker pastes with greater serum viscosity and acidity than tomatoes harvested at other points in the ripening process. The best results were obtained from canned samples of ‘H9888,’‘CXD254’ and ‘H9780.’     

Compositional changes in normal and mutant tomato fruit during ripening and storage

Mutations that drastically slow down fruit ripening known as ‘ripening inhibitor’ (rin) and ‘non-ripening’ (nor) have been incorporated by backcrossing into isogenic lines of the tomato cultivar, Ailsa Craig. F₁ hybrids (rin/+ and nor/+) were then produced by crossing with the recurrent parent. The rates of deterioration of fruit from the hybrid plants were compared with those from the recurrent parent and a typical glasshouse cultivar, Sonatine. Levels of acids and sugars, and also the colour, firmness and dry matter content of the fruit, were measured at two selected stages of ripeness and after storage of the ripe fruit for 10 and 20 days at 20°C. Shelf-life of the ripe fruit was also assessed. Although the acidity fell continuously from a high value early in ripening for all four lines, during storage that in the rin/+ was better and Sonatine was worse than average. Sugar levels generally peaked close to the red stage and fell thereafter, but much variability in this component was encountered. Both cv. Sonatine and Ailsa Craig overcoloured and lost firmness during storage, but the mutant lines survived well. The results suggest that the disadvantage of a high-quality line such as Ailsa Craig in deteriorating quickly once the fruit are fully ripe can be partially overcome through the introduction of one of the ‘non-ripening’ alleles.     

Carotenoids and Their Geometry Isomers in Selected Tropical Fruits

This study determined the carotenoids content in cherry tomato, pink guava, and red grapefruit pulps and juices. Cherry tomato pulp exhibited the highest β-carotene content whereas pink guava pulp had the highest lycopene content. However, β-carotene and lycopene contents in the studied fruit juices were lower than their pulps in the same sample portion. Interestingly, six to twelve cis-isomers of carotenoids were identified in the fruit pulps and juices studied. A higher number of trace amounts of cis-carotenoids was found in fruit pulps as compared to juices. Therefore, consumption of whole fruit is recommended as the studied fruit juices have lower carotenoids content.     

Postharvest Ripening Characterization of Greenhouse Tomatoes

The determination of °Brix, pH, titratable acidity and antioxidant composition such as β-carotene, lycopene, and vitamin C was done in greenhouse “Savoura” tomatoes during maturation. The chromatic values L*, a*, b* were determined at the top surface of the tomato, and its strength-deformation curve was tested with a texturometer. Results pointed out that °Brix and titratable acidity did not change during postharvest, while β-carotene, lycopene, and vitamin C contents increased continuously toward the red stage of tomato. The colour values L*, a*, b*, and ratio a*/b* had a good correlation with the maturity stages. Also, a high correlation between lycopene content and (a*/b*) ratio was found, which was well represented with a second order polynomial function (r² = 0.95). This equation permits to appropriately estimate lycopene content of tomato as a function of its color, without any chemical analysis. During ripening, tomato texture changed from firm turgid to soft and the puncture deformation degree increased. Tomato firmness and chromatic values had a good correlation, and the lycopene content was a logarithm function of firmness (r² = 0.81). The strength in puncture test increased linearly with deformation until the bioyield point. The measured force was analyzed as the sum of the compression and the shear forces. The two force coefficients can be considered as tomato properties, independent of the puncture probe. These coefficients were found to decrease during tomato maturation.     

Effects of variety, ripening condition and ripening stage on the quality of sulphite-free dried mango slices

The influence of cultivar and fruit ripeness on sensory properties and all-trans-β-carotene contents of dried mango slices was evaluated. Different ripeness stages, quantitatively defined by a ripening index (RPI), were generated from a single lot per cultivar by subjecting mature-green mangoes of the cultivars ‘Nam Dokmai’, ‘Kaew’, and ‘Chok Anan’ to different postharvest ripening regimes. Fruits were ripened for 2 and 3 days at 24±2 °C/45–60% relative humidity (RH) and 33±2 °C/50–70% RH, with application of calcium carbide (CaC₂) or 2-chloroethylphosphonic acid (CEPA, Ride^®) beside the control, terminating postharvest ripening when fruit firmness allowed proper peeling and slicing. After ripening, fruits were washed, peeled, sliced and subsequently dried in a conventional tray dryer at 70 °C for 8–10 h, until the water activity of the dried fruits was below 0.65. Mangoes cv. ‘Kaew’, followed by ‘Chok Anan’, were more suitable for drying than cv. ‘Nam Dokmai’ because of superior all-trans-β-carotene contents of the products. Maximum β-carotene contents of dried mango slices from cvs. ‘Chok Anan’ and ‘Kaew’ corresponded to retinol equivalents of 333–383 and 483–905 per 100 g of edible portion (dry weight), meeting daily mean requirements of vitamin A for adults according to FAO/WHO. Similar to the fresh fruit, exponential rise of all-trans-β-carotene contents with increasing fruit ripeness was also observed for the dried products of cvs. ‘Nam Dokmai’ and ‘Chok Anan’. Consistently, accelerated ripening at 33 °C, instead of 24 °C, resulted in higher all-trans-β-carotene contents of dried fruits. Both good sensory acceptance and cultivar-specific maximum all-trans-β-carotene contents of 13–16 and 20–23 mg kg^?1 usually characterised the products of ‘Nam Dokmai’ and ‘Chok Anan’ fruits with RPI levels between 3 and 4. Conversely, fruits cv. ‘Kaew’ of RPI levels above 6 generally yielded products inferior in sensory acceptance and β-carotene contents, while superior product quality was found at higher RPI levels than for the other two cultivars.     

Changes in pH, acids, sugars and other quality parameters during extended vine holding of ripe processing tomatoes

BACKGROUND: Two important quality attributes of processing tomatoes are pH and titratable acidity. These and other quality attributes can be affected by tomato fruit maturity and over‐maturity. We have determined the magnitude of these maturity effects in four processing tomato cultivars commonly grown in California. RESULTS: Allowing tomatoes to remain on the vine for up to 4 weeks after ripening resulted in an increase in fruit pH of between 0.01 and 0.02 unit per day for the four cultivars examined. The increase in pH was paralleled by a decrease in titratable acidity, due to a loss of citric acid. Glucose and fructose concentrations also declined with increasing maturity after ripening. Other quality parameters (color, lycopene, total pectin, pectin solubility, and Bostwick consistency) all showed little change. CONCLUSION: Vine holding of ripe fruit adversely affects quality, especially pH and titratable acidity. Recent problems with high tomato juice pH encountered by tomato processors in California could be the result of increased average fruit maturity at harvest. Copyright © 2011 Society of Chemical Industry     

CHARACTERIZATION OF TOMATO RIPENING PROCESS AS INFLUENCED BY INDIVIDUAL SEAL-PACKAGING AND TEMPERATURE

Tomatoes were individually seal-packaged and ripened at two temperatures, 12 and 21° C. Both the temperature and seal-packaging delayed the tomato ripening process. The delay in ripening due to seal-packaging occurred prior to the ‘turning’ and ‘pink’ USDA color maturity stage when stored at 21° C and 12° C, respectively. Lower concentrations of lycopene were associated with lower chroma values in seal-packaged fruits. Both temperature and seal-packaging prolonged the ripening period but did not affect the firmness values at various color stages of tomatoes.     

Development of a process for the production of a betalain-based colouring foodstuff from cactus pear

Since no process has yet been established for the production of cactus pear juice, the present work aimed at the development of a betalain-based colouring foodstuff from Opuntia ficus-indica cv. ‘Gialla’ and cv. ‘Rossa’ of two seasons applying unit operations typical for fruit juice production. Complete separation of the peels from the pulp and removal of seeds were achieved by carborundum peeling of the frozen fruits and subsequent passing through a finisher. Furthermore, for improved filtration of cactus pear juice different enzyme preparations were tested to degrade pectic-like substances. To monitor quality changes in the course of processing, juice samples were analysed after each processing step in terms of colour and selected chemical parameters. While lightness (L*) and chroma (C*) increased during processing for both cultivars, hue angle (h°) remained unchanged for the yellow cultivar ‘Gialla’, but a slight shift towards red was observed for the red cultivar ‘Rossa’ after pasteurisation. Unexpectedly, even after repeated thermal treatment neither non-enzymatic browning nor HMF formation was observed in juices from both cultivars.Industrial relevanceCactus pear represents a viable alternative to red beet for food colouring purposes: it neither exhibits negative sensorial impact nor high nitrate levels, but offers a broad colour range. However, no attempt has yet been made to benefit from this potential. The process developed is considered suitable for being scaled up to industrial-scale production thus opening an avenue for large-scale cactus pear fruit processing.