Can grafting in tomato plants strengthen resistance to thermal stress?

Grafted and non‐grafted tomato plants were grown at 25 and 35 °C for 30 days. In tomato leaves we analysed total phenols, o‐diphenols, enzymatic activities (PAL, PPO and GPX) and dry weight. Our results indicate that heat stress in both grafted and non‐grafted tomato plants occurred at 35 °C and resulted in (1) increased PAL activity, (2) increased total phenols and o‐diphenols, (3) decreased PPO and GPX activities and (4) decreased dry weight. These results show that high temperature induces the accumulation of phenolics in tomato plants by activating their biosynthesis as well as inhibiting their oxidation. However, the impact of high‐temperature stress was smaller in grafted than in non‐grafted tomato plants. This indicates that grafted plants have a higher degree of resistance against thermal stress if the rootstock is more resistant to thermal stress. Copyright © 2003 Society of Chemical Industry     

Variability in the content of soluble sugars and cell wall polysaccharides in red‐ripe cherry and high‐pigment tomato cultivars

BACKGROUND: Soluble sugars and cell wall polysaccharides are well known for contributing to a range of ‘quality’ characteristics of fresh vegetables such as flavour, texture and healthy properties. Red‐ripe berries of 14 cultivars of cherry tomatoes and four cultivars of high‐pigment tomato hybrids, cultivated in the south of Italy, were analysed for their content of these important qualitative parameters. RESULTS: Sakura appeared to be the cultivar with the highest amount of soluble sugars (53 g kg^?1 fresh weight (f.w.)), mainly glucose and fructose, and, hence the ‘sweetest’ among cherry tomatoes. High‐pigment tomatoes, especially HLY02 and HLY13, showed a soluble sugar content much lower than cherry tomatoes, as expected for industrial, normal‐size tomatoes. Variations in the fructose/glucose ratio, of between 0.68 and 1.48, were evidenced among the different tomato cultivars. Cell wall polysaccharides isolated from whole fresh red‐ripe berries of each cultivar were analysed chemically. The amount of matrix polysaccharides (0.9–3.4 g kg^?1 f.w.) and cellulose (0.16–1.86 g kg^?1 f.w.), as well as their glycosidic composition, showed significant differences among the different cultivars. Cellulose to matrix polysaccharide ratio was highly variable and ranged between 0.06–1.44 and 0.17–0.77 in cherry and high‐pigment tomato cultivars, respectively. CONCLUSION: The differences evidenced in the total soluble sugar and cell wall polysaccharide composition, not only among different types of tomatoes but also different cultivars within the same typology, may play a fundamental role in the quality of tomatoes and deserve further investigations. Copyright © 2008 Society of Chemical Industry     

Chemical composition of tomato (Lycopersicon esculentum) from Tenerife,the Canary Islands

Chemical composition (moisture, ash, total fibre, protein, glucose and fructose), the taste index and maturity were determined in five tomato cultivars (Dorothy, Boludo, Thomas, Dominique, Dunkan) which were cultivated using intensive, organic and hydroponic methods in Tenerife. The chemical composition was similar to most of the data found in the literature. There were many significant differences in the mean values between the analysed parameters according to the cultivar, cultivation method, region of cultivation and sampling period. Glucose and fructose concentrations were strongly and positively correlated, suggesting the common origin of both sugars. The moisture correlated inversely with the rest of the analysed parameters. Applying a stepwise discriminant analysis (DA), low percentages of correct classifications were obtained according to the cultivar and cultivation methods. The correct classification of the tomato samples improved when the DA was applied to differentiate the tomatoes according to the sampling period.     

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     

不同品种龙眼果实加工特性比较研究

以18个龙眼品种的果实为试材,利用常规的加工特性分析方法,进行果实的组成、理化指标、可溶性蛋白、总酚和总抗氧化能力的分析。结果表明:龙眼品种间果实出汁率、可溶性固形物含量、可食率、总酸、糖酸比差异较大,出汁率为36.02%～55.74%,水眼最高(55.74%);华路广眼最低(36.02%),可溶性固形物为11.3%～21.77%,白花木最高(21.77%),青壳宝园最低(11.3%)。18个龙眼品种的多酚氧化酶(PPO)、过氧化物酶(POD)的活性和色泽稳定性差异较大,PPO为0～6.6U,POD为72.7～1816.7U,色泽变化值(ΔE)在30℃时为0.24～3.68,100℃时为7.62～63.53。初步评价:石硖、储粮、白花木、华路广眼和双孖木是适宜于果汁和果酒加工的优良品种。龙眼的总抗氧化能力值在3.73～20.39mmol/L之间,双孖木最高(20.39mmol/L),青壳宝园最低(3.73mmol/L);可溶性蛋白含量分布变幅为45.82～88.8mg/L,石硖最高(88.8mg/L),鸡卵眼最低(45.82mg/L);总酚含量在13.02～749.95mg/L之间,华路广眼最高(749.95...     

Quality changes during ripening of plums (Prunus domestica L.)

Quality changes during fruit ripening after the appearance of fruit colour of four Prunus domestica L. plum cultivars, ‘Jojo’, ‘Valor’, ‘Čačanska rodna’ and ‘Čačanska najbolja’, were investigated during 25 or 33 day periods. Fruit samples were analyzed for fruit weight, firmness, soluble solids content, fruit colour, content of sugars (glucose, fructose, sorbitol and sucrose), organic acids (malic, fumaric and shikimic acids), phenolics (neochlorogenic acid, p-coumaroylquinic acid, chlorogenic acid and rutin) and anthocyanins (cyanidin-3-rutinoside and peonidin-3-rutinoside). Ripening resulted in statistically increased fruit weight and soluble solids, decreased fruit firmness, darker colour of fruits, increased concentration of total sugars, decreased concentration of total acids, and increased concentration of anthocyanins. There was no influence of ripening on the content of phenols. The results show significant influences of cultivar on fruit weight, soluble solids content, firmness, fruit colour, concentration of total acids, SUAC index, concentration of total phenols and anthocyanins in European plums.     

Quality assessment of tomato landraces and virus-resistant breeding lines: quick estimation by near infrared reflectance spectroscopy

BACKGROUND: Several tomato landraces are very popular in south‐eastern Spain for their organoleptic fruit quality, but these cultivars are highly susceptible to several viruses. A breeding programme is being carried out for the introduction of virus resistances into these landraces. In the last steps of our breeding programme a high number of breeding lines must be evaluated for agronomic and organoleptic quality parameters. Near infrared reflectance spectroscopy (NIRS) technology shows considerable promise and is ideally suited to the requirements of breeders. RESULTS: Significant differences between a set of 35 tomato breeding lines, seven landraces and one commercial hybrid were observed for quality and mineral content parameters, suggesting that there are considerable levels of genetic diversity between the cultivar groups studied. Using NIRS on dry samples of tomato constitutes a feasible technique to estimate the content of several minerals (C, N, P, K, Ca, Na, Mn, Mg and Cu) according to the coefficient of determination for calibration (R² > 0.90). NIRS estimations of soluble solids content and titratable acidity obtained were considered useful only for general screening purposes. CONCLUSIONS: NIRS technology may be a useful tool in the selection of lines coming out of tomato breeding programs, allowing a quick estimation of mineral content. However, the estimation of soluble solids content and titratable acidity by NIRS must be improved. Copyright © 2011 Society of Chemical Industry     

不同品种番茄理化指标分析与研究

使用6种不同品种的番茄为实验原料,以可溶固形物含量、VC含量、番茄红素含量、色差为检测指标,分析各品种番茄中理化成分的含量,实验结果表明,里格尔87-5可溶固形物含量为5.3°Bx,其次为UC-82可溶固形物含量为5.1°Bx;不同品种间VC含量差异较大,其中UC-82中VC含量最高为28.9mg/100g;不同品种番茄番茄红素含量差异较大,其中里格尔87-5红素含量较高,可达到6.22mg/100g;在送样的6个品种番茄中,里格尔87-5的A值最大,色泽较好。     

Quantitative Variation of Total Phenols in Fresh Market Tomatoes at Three Stages of Maturity

Analyses for total phenols in extracts of epidermal, placental and pericarp tissue from three tomato cultivars that had been observed to vary in susceptibility to post harvest spoilage by microorganisms showed no significant quantitative variation by cultivar. Quantities of phenols varied significantly (P < 0.05) by maturity and location within the fruit. The highest concentration of phenols was found in the epidermal and placental tissue at the midripe stage of maturity. Quantities were highest in the Patriot cultivar which related to observations that tomatoes from this cultivar were more resistant to microbial infection than were tomatoes from the Floridade and Walter cultivars.     

Chemical characterization of tomato pomace

Tomato‐processing by‐product, also known as tomato pomace, consists of peel and seeds and represents around 4% of the fruit weight. If these wastes remain unused, they not only add to the disposal problem but also aggravate environmental pollution. The aim of this paper is to evaluate the chemical composition of tomato pomace collected at different steps during industrial processing in order to assess the quality of this by‐product. Twenty‐one tomato pomace samples were considered for analysis. Samples corresponded to different steps during tomato processing for paste: seven after pulper, five after finisher, six before turbopress and three after turbopress. Samples were analyzed for moisture content, total and soluble sugars, protein, fat, soluble and total fiber, as well as mineral content. From the results obtained we can conclude that tomato pomace composition (in dry weight basis) is as follows: 59.03% fiber, 25.73% total sugars, 19.27% protein, 7.55% pectins, 5.85% total fat and 3.92% minerals. Copyright © 2006 Society of Chemical Industry     

Physicochemical and bioactive properties evolution during ripening of ‘Ambrunés’ sweet cherry cultivar

The purpose of this paper is to present a study of the development of the principal bioactive compounds and the physicochemical properties of the ‘Ambrunés’ Picota sweet cherry cultivar during its ripening. 5 categories of edible ripeness (termed ’ripening stages’) were determined according to the skin colour. The results show significant increases during ripening in weight, calibre, soluble solids content, fructose, total phenols, total anthocyanins and total antioxidant activity; a non-significant decrease in firmness; and significant decreases in the colour parameters of both skin and flesh and in glucose. The following compounds were identified and quantified using HPLC-DAD/ESI-MS: 5 anthocyanins, of which the most abundant was cyanidin-3-O-rutinoside; 3 hydroxycinnamic acids, principal of which was p-coumaroylquinic acid; a flavonol (rutin); and a flavan-3-ol (epicatechin), which was the least abundant of all the phenolic compounds. Because of the increased levels of bioactive compounds associated with it, ripening stage 5 was considered to represent the highest nutritional and functional quality.     

Effect of conventional and organic production systems on the yield and quality of field tomato cultivars grown in Tunisia

BACKGROUND: The agricultural production system and cultivation practices are critical factors in determining yield and food nutritional quality. Controversy remains regarding whether or not organic foods have a nutritional advantage when compared with their conventionally produced counterparts. In this study the effect of conventional and organic production systems on yield, physicochemical and nutritional properties of four field tomato cultivars (Perfectpeel, Rio Grande, Hypeel 108 and Firenze) was determined. In the organic system, different fertiliser combination treatments were used. RESULTS: When production system data were combined, marketable yield was not affected by cultivar. When averaged across cultivars, organic yield was about 63% of conventional yield. The production system affected fruit soluble solids, pH, titratable acidity and firmness only in some cultivars. However, no effect was found on lycopene and total phenolics in all cultivars. In the organic system, fertiliser combination treatments affected tomato yield of Rio Grande and fruit quality of Firenze and Hypeel 108. A general trend of higher quality data was obtained by using mixed compost C2 combined with its extract and codahumus 20. CONCLUSION: The production system affects tomato yield and some fruit quality attributes. The effect on fruit quality varies among cultivars, thus highlighting the need to use a range of varieties in this kind of study. Copyright © 2009 Society of Chemical Industry     

Characterisation of Pomegranate Juices from Ten Cultivars Grown in Turkey

Pomegranate juices obtained from ten pomegranate cultivars of Turkey were analysed for their sugars, organic acids and the other quality parameters including pH, total soluble solids, and titratable acidity. Statistically significant differences were determined among the cultivars for parameters analysed. Citric acid was the predominant acid of all the cultivars studied. Cultivar “Zivzik,” one of the most popular cultivar in Turkey, showed best scores for total soluble solids (16.9 ± 0.06 °Brix), glucose (84.18 ± 0.42 g/l) and fructose (83.34 ± 0.81 g/l). Pomegranate juices were classified into three groups according to principal component analysis and cluster analysis.     

Effect of cultivar and roasting method on composition of roasted soybeans

BACKGROUND: The composition of raw soybeans and the roasting method have an important impact on the quality of roasted soybeans. The objective of the study was to determine the effect of food‐grade soybean cultivars (IA 2064, IA 1008, IA 1008LF, Prairie Brand 299, Asgrow 2247) and roasting method (oil‐ and dry‐roasting) on the composition of roasted soybeans. RESULTS: Moisture content decreased after roasting, with oil‐roasted soybeans having a significantly lower moisture content than the dry‐roasted soybeans. With the exception of the low linolenic acid cultivar (IA 2064), there were no significant differences in total lipid and fatty acid contents of the five cultivars. Oil‐roasted soybeans had significantly higher lipid content than raw and dry‐roasted soybeans owing to the absorption of oil. The soluble sugars and free amino acids contents of the five soybean cultivars were not significantly different. Decreases in the contents of free amino acids, but not soluble sugars, occurred during roasting. Greater reductions were seen in oil‐roasted soybeans because of the higher roasting temperature. CONCLUSION: Roasting method, rather than cultivar, had the greatest effect on the composition of roasted soybeans. The food‐grade soybean cultivars evaluated in this study were similar in composition. Copyright © 2009 Society of Chemical Industry     

The influence of ripening and crop year on quality indices,polyphenols, terpenic acids,squalene, fatty acid profile,and sterols in virgin olive oil (Koroneiki cv.) produced by organic versus non‐organic cultivation method

The chemical composition of virgin olive oil is determined by numerous factors. The aim of this study was to evaluate the influence of the olive ripening stage, and crop year on the quality indices of Koroneiki cv. virgin olive oil of organic vs non‐organic cultivation. Drupes of organic and of non‐organic cultivation were sampled at four successive ripening periods in crop years 2000 and 2004. Quality indices, total and simple polyphenols, terpenic acids, squalene, fatty acid profile, and sterols were measured. Statistical analysis demonstrated that peroxide value differed according to cultivation method and according to crop year. Organic Koroneiki cv. olive oils exhibited higher total phenols content. Total phenols differed mainly according to crop year and maturation phase, but also according to cultivation method. Total unsaturated and saturated fatty acids differed according to cultivation method, crop year and maturation. Oleic and palmitoleic acids varied according to cultivation method and according to maturation process. Cholesterol, campesterol and stigmasterol differed according to maturity, while β‐sitosterol differed according to crop year. Overall, olive oil from organic cultivation was of superior quality compared to non‐organic, while composition of olive oils was greatly variable during maturation, whereas it was also affected by the crop year.     

No improvement in fruit quality through chemical flower thinning in sweet cherry (Prunus avium L.)

BACKGROUND: Chemical flower thinning with ammonium thiosulfate (ATS) was applied on branches of sweet cherry (Prunus avium L.) cultivars ‘Blaze Star’, ‘Samba’, ‘Techlovan’ and ‘Merchant’ (all grafted on GiSelA 5) in a two‐year field study in 2006 and 2007. Different concentrations of ATS (8.82 and 17.64 g L^?1) and different application times were studied. Fruit quality parameters analysed included crop load, fruit size, fruit weight, flesh/stone ratio, content of soluble solids, pH value and content of titratable acids. RESULTS: Crop load was significantly affected (P < 0.01) by application, cultivar and year. Fruit size, fruit weight and content of titratable acids were not improved by any of the application strategies. An influence of cultivar and application on pH value was observed (P < 0.05). Flesh/stone ratio was significantly enhanced (P < 0.05) in ‘Blaze Star’ only, while content of soluble solids was significantly affected in ‘Techlovan’ only in 2007. CONCLUSION: No general improvement in quality parameters was achieved by chemical flower thinning in the P. avium cultivars studied over a two‐year field experiment. Copyright © 2009 Society of Chemical Industry     

Evaluation of antioxidative performance of tomato extracts obtained by different methods

BACKGROUND: Two extraction methods employing tetrahydrofuran and phosphate buffer (pH 7.4) respectively were used to process tomatoes. The antioxidant contents and antioxidative properties of extracts of four tomato cultivars were measured. To evaluate the overall antioxidative capacity of the tomato extracts, an antioxidative performance index (API) was used, defined as the average of four antioxidative assays, i.e. relative reducing power, ferrous ion‐chelating ability, 2,2‐diphenyl‐1‐picrylhydrazyl free radical‐scavenging activity and superoxide radical‐scavenging activity. RESULTS: A linear correlation between the total antioxidant content (TAC) and API of tomato extracts was found that was independent of the extraction method and tomato cultivar. CONCLUSION: The concept of representing multiple antioxidant activities by a single index is useful for evaluating the overall antioxidative capacity of antioxidants in tomatoes. Copyright © 2007 Society of Chemical Industry     

HPLC-DAD detection of changes in phenol content of red berry skins during grape ripening

With increasing concern for a demand from consumers for natural products, there is a wide interest in bioactive substances. The new frontier of dietary quality is the study and promotion of functional foods. Phenols are among the most important functional molecules. Red grape and red wine contain bioactive products as phenols. Changes occurring in the concentrations of phenols, such as hydroxycinnamic tartaric acids (hctas), flavonols, and anthocyanins in berry skins, were measured during growth and ripening of four red grape cultivars, Alicante, Black Malvasia, Nerello, and Prunesta (Vitis vinifera L.), cultivated in a coastal location of the Reggio Calabria Province (Southern Italy). These cultivars are the most popular and are considered to be the most suitable grape cultivars for cultivation in the Tyrrhenian side of the Reggio Calabria Province. Fractioning of three phenolic classes was conducted through the adsorbing resin Serdolit XAD-2. Each single phenolic fraction was analyzed by liquid chromatography with diode array detector (HPLC-DAD). Each cultivar presented a different chromatographic profile particularly for anthocyanins. The cultivar Nerello was distinguished from other for its high content of anthocyanins. The rate, at which the concentration of hctas, flavonols and anthocyanins increased, varied greatly among the cultivars. The hydroxycinnamic tartaric acid profile varied in the studied cultivars, in fact in Alicante, Black Malvasia and Prunesta cultivars, the predominant was trans-coumaroyl tartaric acid, while in Nerello cultivar, trans-caffeoyl tartaric acid was the most abundant. In addition, the results showed that amounts of phenolic compounds contained in grape skin changed throughout the grape ripening process.     

Analysis of organic acid content in cultivars of tomato harvested in Tenerife

The determination of organic acids in tomato samples was optimized using the HPLC method with on-line photodiode array detection, previous to extraction with 80% ethanol at room temperature and clean-up in Accell Plus QMA cartridge. The organic acids (oxalic, pyruvic, malic, citric, fumaric and ascorbic), Brix degree, acidity and pH were determined in five tomato cultivars (Dorothy, Boludo, Dominique, Thomas and Dunkan) harvested in Tenerife. There are several significant differences among cultivars in the concentration of many acids. The cultivation method, sampling period and the region of production were also considered. Citric, malic and oxalic acids were the major organic acids in all the cultivars. Some significant differences in the studied parameters were observed between the cultivars. The cultivation method and sampling period influenced in a variable way the studied parameters, depending on the tomato cultivar. The production region influenced the ascorbic acid concentration of the tomatoes. Applying stepwise discriminant analysis, it was found that the sampling period is more important in the differentiation of the tomato samples than the cultivar, cultivation method and production region.     

Polyphenolic composition and content in the ripe berries of wild Vitis species

To explore wild genetic resources for improving fruit and processing quality of cultivated grape cultivars, the polyphenolic composition and content in the ripe berries of 147 grape accessions from 16 Vitis species for two consecutive years were characterised. A total of 48 polyphenolic compounds, including 28 anthocyanins, 6 flavonols, 6 flavanols, 6 hydroxycinnamic derivatives, and 2 hydroxybenzoic acids, were identified via HPLC-MS and quantified by HPLC-DAD. These wild grape species had unique presence of abundant di-glucoside derivatives of anthocyanins. In addition, anthocyanins in most wild species were predominantly nonacylated. The mean contents for anthocyanins, flavanols, flavonols, hydroxycinnamic derivatives, and hydroxybenzoic acids were 9.610, 0.769, 0.093, 0.441 and 0.027 mg g⁻¹ FW, respectively. They were about 2 to 10 folds higher than their respective counterparts in the most widely cultivated grape species Vitis vinifera. As expected, most of these groups of compounds were correlated negatively with berry weight, but positively with the content of total soluble solids.