Pepper antioxidant composition as affected by organic,low‐input and soilless cultivation

BACKGROUND: The aim of this work was to study the effects of organic (O), low‐input (LI) and soilless (SL) cultivation on pepper nutritional quality and antioxidant activity. For that, 24 commercial greenhouses were selected following strict criteria in order to reduce the influence of environmental conditions and realistically reflect commercial production systems. Fruits were harvested at two maturity stages (green and red) and three harvesting times during two consecutive years. RESULTS: Pepper antioxidant activity mainly stemmed from water‐soluble compounds, including organic acids and phenolic compounds. Only some differences in sugars and malic and citric acid concentrations were detected between the O and LI systems. Sugars, phenolic compounds, ascorbic acid and hydrophilic antioxidant activity were higher in the SL system. In spite of these differences, overall differences between harvesting times or between years were far greater than those due to the cropping system. CONCLUSION: The main differences in the nutritional quality of pepper fruits were observed between the soil (O and LI) and SL (the most favourable) systems. The results highlight the importance of comparing different harvesting times and years in order to study the effect of cropping system on a specific crop. Copyright © 2009 Society of Chemical Industry     

Differential effect of organic cultivation on the levels of phenolics,peroxidase and capsidiol in sweet peppers

BACKGROUND: Coincident with the changes in agricultural practices from conventional to organic, changes in the nutrient composition of fresh fruits and vegetables have been identified. The levels of peroxidase, total phenolics content, and capsidiol activity in organic as compared with conventional sweet pepper fruit were examined in this study. In order to avoid interferences of environmental factors on the studied parameters, the sweet peppers were grown (organically and conventionally) in a greenhouse under the same soil and climate conditions. RESULTS: Peroxidase was partially purified using the Triton X‐114 method and both organic and conventional peppers had the same isoenzymatic form. However, peroxidase activity in organic sweet peppers was higher than in conventional ones, in both maturity stages studied. The level of total phenolics compunds was also higher in organic than in conventional sweet peppers. With respect to the capsidiol activity, expressed as inhibition of fungus growth, it was not affected by the cultivation method at the green mature stage. However, at the red mature stage, organic sweet peppers showed higher capsidiol activity than those grown under the conventional system. CONCLUSION: Sweet peppers grown under organic culture have a maturity‐related response, with high levels of phenolic compounds, and peroxidase and capsidiol activity that contribute to disease resistance in organic farming. Copyright © 2007 Society of Chemical Industry     

Bioactive Compounds and Fruit Quality of Green Sweet Pepper Grown under Different Colored Shade Netting during Postharvest Storage

In this study, influence of 3 types of photo‐selective nets (pearl, red and yellow) and a standard black net on marketable yield, fruit quality and bioactive compounds after postharvest storage was investigated. Percentage marketable fruits were higher in green sweet peppers produced under the pearl nets. Fruits produced under the pearl nets showed higher fruit mass, firmness, chlorophyll content, ascorbic acid content, antioxidant scavenging activity after postharvest storage. Red/far red photon ratio under the pearl net could have improved the ascorbic acid content and the antioxidant scavenging activity in green peppers. Green sweet peppers grown under the pearl nets had higher hue values and maintained green color longer. Our results showed the impact of modified light quality on the bioactive compounds of green sweet pepper during postharvest storage.     

Effect of manure and mineral fertilisation on pepper nutritional quality

BACKGROUND: The influence of farming systems on fruit quality remains controversial and the different aspects associated with each agricultural management system need to be studied separately to elucidate any specific effect on fruit quality. To this end, a greenhouse experiment was conducted to examine the effect of the usual fertilisation guidelines for pepper cultivation on the nutritional quality of fruits (sugars, vitamin C, total phenolic compounds, chlorophylls, total carotenoids and antioxidant activities in the hydrophilic (HAA) and lipophilic (LAA) fractions). Treatments included manure amendment combined with synthetic fertiliser applied at the rates recommended for organic (T1), low‐input (T2) and conventional (T3) practices. RESULTS: Pepper composition was not affected by increasing mineral fertilisation. In addition, treatment had no significant effect on HAA or LAA. The antioxidant activity of both the hydrophilic and lipophilic fractions increased from the green to the red stage of ripening. HAA contributed about 80% of the total antioxidant activity. CONCLUSION: Pepper response to mineral fertilisation seems to be less pronounced than that of other fruits, since antioxidant concentrations did not increase with increasing fertiliser application. Antioxidant activity in pepper was mainly linked to hydrophilic compounds (vitamin C and phenolic compounds). Ripening was the most important factor determining the fruit antioxidant composition. Copyright © 2009 Society of Chemical Industry     

Cultivation approach for comparing the nutritional quality of two pepper cultivars grown under different agricultural regimes

The aim of this study was to assess the influence of the cropping system (organic or conventional) and the growth medium (soil or soilless) on the antioxidant content of peppers from Almuden and Quito cultivars. This cultivation study complements a previous farm study. For both cultivars, organic cultivation led to higher fruit lipophilic antioxidant content than conventional management but differences in the hydrophilic fraction were not observed. The effect of the growth medium on pepper composition depended on the studied cultivar. In Almuden, neither the hydrophilic nor the lipophilic fractions were affected by the growth medium, while in Quito most compounds showed higher values in soil-grown plants. Taking into account the results from the present and the previous farm study we conclude that the effect of organic vs. conventional cultivation on pepper quality can be attributed to the different nutritional regimes and other factors associated with the agricultural system. However, both aspects are not necessarily different in organic and conventional commercial crops. The effect of the growth medium (soil or soilless) on pepper quality depended on the cultivar: Almuden was not affected by the growth medium and Quito was seen to be less suitable for soilless cultivation.     

Influence of soil type and storage conditions on sensory qualities of fresh‐cut cantaloupe (Cucumis melo)

On‐farm cantaloupe (Cucumis melo) production as well as fresh‐cut storage duration can affect postharvest fruit sensory attributes. Both effects of soil type during production of cantaloupe fruits and storage temperature after fresh‐cut processing on sensory flavour and texture attributes were determined. Melons grown in sandy loam vs heavy clay soil were lower in sweet aromatic and sweet taste and higher in moisture release and fermented flavour. Fruity/melon, sweet aromatic, surface wetness, hardness and moisture release attributes decreased while fermented and sour flavour increased during storage regardless of soil type. During storage an increase in peroxidase activity occurred in fruits produced in sandy loam soil but decreased in fruits produced in clay soil. Clay soil appeared to have some advantages over sandy loam soil in producing cantaloupe fruits with better sensory quality attributes. Storage temperature conditions in this experiment (4 °C for 10 days or 4 °C for 4 days plus 10 °C for 6 days) did not have a statistically significant effect on these sensory attributes. Copyright © 2004 Society of Chemical Industry     

基于转录组分析氯化钙对青圆椒采后机械损伤品质的影响

为探究氯化钙处理对青圆椒采后机械损伤品质的影响,通过高处坠落的方法模拟青圆椒运输过程中受到的机械损伤,利用1 mmol/L氯化钙溶液浸泡处理,测定贮藏期间青圆椒的硬度、色泽及感官品质,并通过高通量测序技术进行转录组分析。结果表明,1 mmol/L氯化钙处理能延缓青圆椒转红、软化及腐烂。同时本研究确定了与青圆椒果实色泽转变、质地变化和风味香气产生的相关基因,鉴定了参与植物激素信号转导途径的关键酶和转录因子,分析了氯化钙处理对机械损伤青圆椒果实贮藏品质的影响。氯化钙可能通过抑制编码双功能15-顺式八氢番茄红素合酶（bifunctional 15-cis-phytoene synthase,PSY）和辣椒红色素/辣椒红色素合酶（capsanthin/capsorubin synthase,CCS）等基因的上调来抑制类胡萝卜素的合成,通过抑制纤维素合酶A（cellulose synthase A,Ces）、内切-1,3-β-葡萄糖苷酶（endo-1,3-β-glucosidase 4,β-Glu）和内切葡聚糖酶25（endoglucanase 25,EG25）等基因的下调来缓解其软化,并通过影响青圆椒中某些转录因子、植物激素和香气风味相关基因的表达,进而影改善有机械损伤的青圆椒果实的表观品质。结论：氯化钙处理可以有效延缓机械损伤青圆椒果实品质的劣变,延长青圆椒果实的贮藏期。     

Anti-oxidant content of different coloured sweet peppers, white, green, yellow, orange and red (Capsicum annuum L.)

Five different coloured sweet peppers (Capsicum annuum cv. Signal), white, green, yellow, orange and red were analysed for total carotenoids, α‐tocopherol, sugars (glucose, fructose and sucrose), organic acids (citric and ascorbic acids) and anti‐oxidant properties. The mature fruits, ‘Signal Red’, ‘Signal Orange’ and ‘Signal Yellow’ contained higher carotenoids, α‐tocopherol, sugars and organic acids than the immature fruits, ‘Signal Green’ and ‘Signal White’. Among the mature fruits, ‘Signal Red’ was the highest in total carotenoids [9.15 mg (100 g)^?1 of fresh weight] while ‘Signal Orange’ was the highest in α‐tocopherol [5.40 mg (100 g)^?1 of fresh weight]. ‘Signal Red’ and ‘Signal Orange’ contained the most sugars and organic acids. The suppression of 2,2′‐azobis (2,4‐dimethylvaleronitrile) (AMVN)‐induced oxidation of methyl linoleate by the acetone extracts from the coloured sweet peppers resulted as follows: ‘Signal Red’ > ‘Signal Orange’ ≈ ‘Signal Yellow’ > ‘Signal Green’ ≈ ‘Signal White’. The order of 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging activities of the acetone extracts was similar to that of suppression of methyl linoleate oxidation.     

Antioxidant compounds in green and red peppers as affected by irrigation frequency,salinity and nutrient solution composition

BACKGROUND: There is a need to encourage more sustainable agricultural practices, reducing inputs of water and fertilisers while minimising any negative impact on fruit quality. The effect of irrigation frequency, salinity and potassium and calcium fertilisation on the content of bioactive compounds and quality attributes of green and red peppers grown with and without substrate was evaluated. RESULTS: Low irrigation frequency and salinity improved the quality attributes (dry matter, soluble solids content and titratable acidity) of pepper. Low irrigation frequency increased vitamin C content by 23% in green peppers, while in red fruits it was not affected. In contrast, total carotenoids and provitamin A only increased in red fruits by 30% and 15%, respectively, as a consequence of low irrigation frequency. When the effect of potassium and calcium doses was investigated, it was shown that a high proportion of potassium increased the vitamin C, provitamin A and total phenolic content of red and green peppers, whereas pepper grown at low calcium doses, presented the highest content in carotenoids and provitamin A. CONCLUSION: Low irrigation frequency and fertilisation with high potassium and low calcium doses improved pepper quality increasing the content of bioactive compounds. Copyright © 2009 Society of Chemical Industry     

Polyphenol oxidase,total phenolics and ascorbic acid changes during storage of minimally processed ‘California Wonder’ and ‘Quadrato d'Asti’ sweet peppers

A growing sector of ‘minimally processed’ vegetables market is represented by sweet peppers, whose quality may be affected by enzymatic activities. Among these, polyphenol oxidase leads to browning reactions, which is a major cause of quality loss. This research aimed at assessing the changes in PPO activity, total phenolics and ascorbic acid throughout a 30-days cold storage in minimally processed green (cv. ‘California Wonder’), yellow and red (cv. ‘Quadrato d'Asti’) sweet peppers. At day 0 PPO was active in red and yellow fruits but not in green ones, where it started to show relevant activity from the 3rd week of storage. At the end of the storage period (day 30), PPO activity was 1.36, 0.94 and 0.61 U/g d.m. in yellow, red and green peppers, respectively. Total phenols content was highest in green peppers, followed by red and yellow ones. In green fruits it increased up to the 3rd week of storage, decreasing afterwards, whilst in red and yellow fruits phenols content progressively declined after the 2nd week. Yellow fruits showed the highest ascorbic acid content, followed by red and green ones.Results confirm that green peppers ‘California Wonder’ are more suitable to minimal processing than yellow and red fruits.     

Determination of optimum harvest maturity and physico-chemical quality of Rastali banana (Musa AAB Rastali) during fruit ripening

BACKGROUND: A series of physico‐chemical quality (peel and pulp colours, pulp firmness, fruit pH, sugars and acids content, respiration rate and ethylene production) were conducted to study the optimum harvest periods (either week 11 or week 12 after emergence of the first hand) of Rastali banana (Musa AAB Rastali) based on the fruit quality during ripening. RESULT: Rastali banana fruit exhibited a climacteric rise with the peaks of both CO₂ and ethylene production occurring simultaneously at day 3 after ripening was initiated and declined at day 5 when fruits entered the senescence stage. De‐greening was observed in both of the harvesting weeks with peel turned from green to yellow, tissue softening, and fruits became more acidic and sweeter as ripening progressed. Sucrose, fructose and glucose were the main sugars found while malic, citric and succinic acids were the main organic acids found in the fruit. CONCLUSION: Rastali banana harvested at weeks 11 and 12 can be considered as commercial harvest period when the fruits have developed good organoleptic and quality attributes during ripening. However, Rastali banana fruit at more mature stage of harvest maturity taste slightly sweeter and softer with higher ethylene production which also means the fruits may undergo senescence faster than fruit harvested at week 11. Copyright © 2011 Society of Chemical Industry     

Postharvest evaluation of soilless-grown table grape during storage in modified atmosphere

BACKGROUND: Soilless growth systems, developed mainly for vegetables and ornamental crops, have also been used recently as an alternative to soil culture for table grape in order to achieve optimal production performance. In this study, sensory, physical and chemical parameters were analysed in table grapes obtained from soil and soilless growth systems at harvest and during storage in air or modified atmosphere. RESULTS: At harvest, soilless‐grown berries were 30% firmer than those grown in soil. Moreover, they showed 60% higher antioxidant activity and total phenol content than soil‐grown fruits. Modified atmosphere storage resulted in a better quality of table grapes compared with those stored in air. Furthermore, soilless growth was more suitable than soil growth for preserving visual quality and controlling rachis browning and weight loss. CONCLUSION: Since the soilless system produces berries that are cleaner and of higher quality than those grown in soil, the implementation of soilless growth for the production of health‐promoting and convenience fruits is suggested. Copyright © 2011 Society of Chemical Industry     

Effect of organic growing systems on sensory quality and chemical composition of tomatoes

Tomato plants were grown in the greenhouse in the soil, in confined beds, or in combined beds where the roots could also develop in the soil outside the bed. The beds were filled with compost based on clover grass hay, deep litter and peat and harvested in early summer and autumn in 2002 and 2003, and in the soil treatment the same compost was incorporated into the soil. The tomato fruit quality was assessed by sensory analysis and content of chemical components as, e.g. dry matter, soluble solids, citric acids and volatile components. The content of minerals was mainly determined to evaluate possible limitations in nutrient supply. Due to only minor effects of growing systems on sensory quality and chemical composition of tomato fruits it is concluded that it is possible to produce tomato fruits in confined and combined soil bed systems without any loss in eating quality. Actually the results indicate that a slight increase in quality of tomatoes from the confined and combined systems is obtained. The present result points to the fact that confined and combined growing systems may be new relevant commercial growing systems, in which the quality of tomatoes seems to be ensured, and in which nutrient loss and root diseases contamination can be reduced.     

高湿贮藏对青椒果实冷害和抗氧化活性的影响

为探究高湿贮藏对减轻青椒果实冷害的作用及其与抗氧化活性的关系,将青椒果实放置于4 ℃、相对湿度分别为96%～99%和70%～75%的干雾控湿高湿冷库和普通低湿冷库中贮存15 d,每3 d测定果实冷害、品质和抗氧化系统相关指标变化。结果表明,高湿贮藏可显著延缓青椒果实的冷害指数、相对电导率和质量损失率的上升及硬度的下降,保持较高的叶绿素、抗坏血酸、总酚和总黄酮含量。与低湿贮藏相比,高湿贮藏还可显著提高超氧化物歧化酶、过氧化氢酶、过氧化物酶和抗坏血酸过氧化物酶的活力,保持较高的1,1-二苯基-2-三硝基苯肼和羟自由基清除率,减少超氧阴离子和过氧化氢的积累。这些结果表明,高湿贮藏可维持青椒果实较高的抗氧化活性,从而抑制活性氧对青椒的伤害,减少果实冷害的发生。     

THE COMPOSITION OF TWO SPANISH PEPPER VARIETIES (FRESNO DE LA VEGA AND BENAVENTE‐LOS VALLES) IN DIFFERENT RIPENING STAGES

ABSTRACT

The chemical composition of two traditional varieties of Spanish peppers, “Fresno de la Vega” and “Benavente‐Los Valles” harvested in the provinces of León and Zamora, respectively, at different ripening stages (green mature, breaker and red) were evaluated. Herein we report the global composition, mineral and trace element contents, and the most relevant physicochemical parameters of each variety of pepper collected in 2 consecutive years. Both pepper varieties showed a similar chemical composition, except in vitamin C content, which resulted to be about 70% higher in Fresno de la Vega peppers. Red ripe fruits were high in total carbohydrates, fructose, glucose, sucrose, fat (64.5, 29.14, 25.57, 2.94, 1.79/100 g dry weight, respectively) and total soluble solids (6.83°Brix). Ascorbic acid content also increased progressively during ripening, reaching a mean value of 1.81 mg/100 g dry weight for Fresno de la Vega peppers. Potassium was the most abundant of the analyzed elements in the all samples, followed by phosphorus, magnesium, calcium and sodium. The order of the levels of the trace elements was iron > manganese > zinc > copper.

PRACTICAL APPLICATIONS

This report underscores the potential value of two traditional varieties of Spanish peppers and provides information on their composition during ripening to decide the proper harvesting time, which can be useful in the food industry.     

A COMPARISON OF LIPID AND LIPID/HYDROCOLLOID BASED COATINGS TO EVALUATE THEIR EFFECT ON POSTHARVEST QUALITY OF GREEN BELL PEPPERS

Maintaining quality of harvested fruit and vegetables is a challenge. The study investigated the effects of two lipid and lipid/hydrocolloid based coatings on maintaining post harvest quality of green bell peppers. Quality characteristics measured during the 4‐week storage period included: respiratory rate, moisture content (weight loss), chlorophyll content, puncture force, ascorbic acid (AA) and dehydroascorbic acid (DHA) contents. No significant differences (P>0.05) between uncoated and coated peppers were noted for respiration rate, puncture force, chlorophyll content, and AA. Significant differences (P<0.05) were found in moisture content and DHA content in the uncoated and coated peppers. Continued research is needed in creating more sophisticated bilayer coatings to enhance product shelf‐life.     

Effects of harvesting seasons and maturity stages on internal characteristics of the mangosteen having different surface properties

Translucent flesh disorder is a major internal physical disorder of mangosteen. The internal characteristics of smooth‐ and coarse‐surface fruits in relation to their respective specific gravity values and sensory characteristics were evaluated for suitable grading process. Study on percentage of the internal characteristics was performed in different external characteristics, different harvesting seasons and different maturity stages of mangosteen. Results showed that internal physical disorders of smooth‐surface fruits were higher than coarse‐surface ones at the level of 63% and 19%, respectively. Average specific gravity of normal‐flesh fruits, mild translucent‐flesh fruits and moderate‐to‐severe translucent‐flesh fruits were observed as 0.97, 1.00 and 1.01, respectively. The sensory characteristics: sweetness, flavour and overall acceptability were significantly (P < 0.05) higher for coarse‐surface fruits compared with smooth‐surface fruits. Both results were inconsistent with market price in which smooth fruit was 50% higher than coarse‐surface fruit.     

Use of UV-C treatments to maintain quality and extend the shelf life of green fresh-cut bell pepper (Capsicum annuum L.)

Abstract: The objective of this work was to select a Ultraviolet‐C (UV‐C) treatment for fresh‐cut mature green bell pepper, and to evaluate the effect of its combination with refrigeration on quality maintenance. Bell pepper sticks were treated with 0, 3, 10, or 20 kJ/m² UV‐C in the outer (O), inner (I), or both sides of the pericarp (I/O) and stored for 8 d at 10 °C. During the first 5 d of storage, all UV‐C treatments reduced deterioration as compared to the control. The treatment with 20 kJ/m² I/O was the most effective to reduce deterioration, and was used for further evaluations. In a second group of experiments, mature green bell pepper sticks were treated with 20 kJ/m² I/O, stored at 5 °C for 7 or 12 d and assessed for physical and chemical analysis, and microbiological quality. UV‐C‐treated fruit showed lower exudates and shriveling than the control. UV exposure also reduced decay, tissue damage, and electrolyte leakage. After 12 d at 5 °C, UV‐C irradiated peppers remained firmer and had higher resistance to deformation than the control. The UV‐C treatments also reduced weight loss and pectin solubilization. UV‐C exposure decreased the counts of mesophile bacteria and molds, and did not affect acidity or sugars. UV‐C‐treated fruit stored for 0 or 7 d at 5 °C did not show major differences in antioxidants from the control as measured against DPPH^? or ABTS^?+ radicals. Results suggest that UV‐C exposure is useful to maintain quality of refrigerated fresh‐cut green pepper. Practical Application: Exposure to UV‐C radiation before packing and refrigeration could be a useful nonchemical alternative to maintain quality and reduce postharvest losses in the fresh‐cut industry.     

Sustainable nitrogen fertilisation in sweet pepper: assessing growth and fruit quality and the potential nitrate pollution from different organic manures

BACKGROUND: The use of organic cultivation with manures does not avoid the risk of high nitrate concentrations if nutrient management is inefficient. So we studied the influence of three organic manures combined or not with additional chemical fertilisers on growth and yield of sweet pepper (Capsicum annuum L.), and on the soil and plant N concentrations. RESULTS: After 3 years of organic cultivation, poultry manure caused the highest soil pollution. The evolution of nitrate and organic matter in soil showed a pattern close to that of plant growth. The addition of mineral fertiliser increased vegetative growth and yield, and a cumulative season effect was observed. In treatments with no additional mineral fertiliser N translocation from leaves to fruits happened. A cumulative effect of seasons on fruit quality and a reduction near to 30% was observed in the first fruit quality category after 3 years. The fruit vitamin C content was reduced by increasing N fertilisation. CONCLUSION: The effects of organic fertiliser on soil and plant growth and yield depended on the type of manure used, its rate, and consecutive crop seasons. Horse manure gave the best combination of agricultural and environmental characteristics and could be used without additional fertigation. © 2012 Society of Chemical Industry