Soluble Pectin Content Research Articles

Influences of 1-MCP on AC Tomato Fruit Softening

The influences of 1-MCP on AC tomato fruit softening were investigated. Ethylene production, flesh firmness, protopectin content, soluble pectin content and polygalacturonase (PG) activity were used to evaluate the quality of tomato fruit. It was shown that 1.0 and 1.5 μL/L 1-MCP treatment significantly decreased the levels of ethylene production, and inhibited flesh firmness and protopectin content decline and polygalacturonase activity increase. At last, it was concluded 1.0 μL/L 1-MCP treatment on AC tomato fruit was the best determining economy.

Pectinase and naringinase help to improve juice production and quality from pummelo (Citrus grandis) fruit

Pectinase and naringinase were investigated for improving the production of pummelo juice by increasing the juice yield and eliminating juice bitterness. Compared to a control, the enzymatic treatment significantly (p<0.05) increased the juice yield, soluble pectin and total soluble solid (TSS) contents, and the clarity, while decreasing the concentrations of the bitter chemicals naringin, limonin, and nomilin. A combined processing treatment of peeling and enzymatic hydrolyses using 5U/g of pectinase and 0.4 U/g of naringinase at 50oC for 60 min resulted in a juice yield of 42.3%, a TSS content of 11.4oBx, a titrable acidity (TA) of 0.96%, a vitamin C concentration of 38.4 mg/100 mL, and concentrations of naringin, limonin, and nomilin of 42.4 μg/mL, 33.5 μg/mL, and 13.3 μg/mL, respectively. The enzymatic method was effective and practical for production of high quantity pummelo juice.

Effect of bentonite/potassium sorbate coatings on the quality of mangos in storage at ambient temperature

The use of bentonite coatings for mango preservation was investigated. Mangos were coated with bentonite and bentonite loaded with potassium sorbate at ambient temperature. The major properties of quality and physiology assessed including color change, decay index, weight loss, respiration intensity, soluble sugar content, titratable acidity, vitamin C content, soluble solids content, protopectin content, and soluble pectin content. Results indicated that mangos treated by either bentonite or bentonite loaded with potassium sorbate exhibited reduced decay, delayed postharvest ripening, decreased water loss, maintained high vitamin C levels, preserved titratable acidity, and no changes in flavor. These effects were greater for bentonite loaded with potassium sorbate than for pure bentonite. Overall results suggest that bentonite and bentonite loaded with potassium sorbate coatings could extend the shelf-life of mangos with optimum quality.

The Quality Change of Mushroom &lt;i&gt;Agaricus bisporus S&lt;/i&gt;tored in the Modified Atmosphere Package with Silicon Gum Film as Window

In order to evaluate the quality change for stored Agaricus bisporus, mushrooms were stored in modified atmosphere packages with and without silicon gum film windows for 15 days. The results shown that the contents of total sugar, protein and protopectin of the Agaricus bisporus stored in packages with silicon gum film as windows decreased more slowly than that of Agaricus bisporus stored in packages without silicon gum film as windows, and the contents of crude fiber and water soluble pectin of the Agaricus bisporus stored in packages with silicon gum film had fewer increase. These indicated that the Agaricus bisporus stored in packages with silicon gum film as windows kept better taste, and had better quality.

Texture and Pectin Content of Four Frozen Fruits Treated with Calcium

In this study, apple, mango, cantaloupe and pineapple cubes were immersed in a 1% calcium chloride solution before being frozen at −40C. The presence of calcium in these fruits did not significantly affect the total pectin content either before or after the freezing and thawing process, whereas it caused a decrease in the water soluble pectin content of all fresh and frozen-thawed fruits except for pineapple. For fresh fruit, calcium significantly increased the firmness of cantaloupe and mango. However, subsequent to freezing and thawing, only the frozen-thawed calcium treated mango had a significantly higher firmness and lower drip loss than the untreated samples. Calcium treatment did not cause changes to the microstructure of either fresh or frozen-thawed fruits. The firmness scores of the fruits tested by trained panelists corresponded with the results from the instrument and the panelists did not detect the bitterness of calcium chloride in the frozen-thawed samples. Practical Applications Freezing tends to disrupt the structure of living cells in fruit tissues which can cause poor texture and high drip loss. The findings of this study provide data as to the role of calcium on the physicochemical properties of frozen fruits. The application of calcium was appropriate on some frozen fruits. Both the instrumental analysis and sensory evaluation confirmed the suitability of the immersion in 1% calcium chloride to improve texture of frozen mango. This process did not cause a bitter taste in all frozen fruit samples. Since a diverse range of fruit types were used in this study, the results are broadly applicable.

Métodos para a climatização de bananas 'Prata-Anã' produzidas na Amazônia Setentrional Brasileira

O objetivo, neste trabalho, foi avaliar o uso da climatização para a uniformização de bananas 'Prata-Anã' produzidas em Boa Vista-RR. Após colhidos, os frutos foram selecionados no formato de buquês, sanitizados, climatizados por abafamento com lona plástica ou por imersão em solução de Ethrel®, embalados com filme de polietileno de baixa densidade e armazenados por quatro períodos de tempo (0; 10;20 e 30 dias) a 12 ± 1 ºC e 93 ± 2% de UR. Após cada período de armazenamento refrigerado (AR) os frutos foram submetidos ao armazenamento em condições ambiente (22 ± 1 ºC e 75 ± 3% UR), retirados das embalagens plásticas e sendo analisados após 1; 2; 3 e 4 dias. As seguintes análises foram realizadas: perda de massa fresca, coloração da casca, produção de etileno e CO2, atividade das enzimas pectinametilesterase e poligalacturonase, acidez titulável (AT), pectina total e solúvel, amido e sólidos solúveis (SS). Não houve diferenças significativas entre os métodos de climatização, porém verificou-se que, quanto maior o período de AR e de condicionamento, menor foi o período de conservação das bananas 'Prata-Anã'. Ficou evidenciado, também, que a climatização, independentemente do método utilizado, deve ser realizada em até 20 dias após a colheita, nas condições de AR aqui testadas. Nessas condições, foi possível manter a qualidade sensorial das bananas por até 3 dias após a retirada dos frutos do armazenamento refrigerado.

THE EFFECTS OF PIECE SIZE AND STORAGE TEMPERATURES ON MINIMALLY PROCESSED 'AURORA-1' PEACHES

The production of minimally processed fruit has increased significantly in the last few years due to the high nutritional value, convenience and safety of minimally processed fruit. The objective of the present study was to evaluate the effects of the conservation temperature and processing conditions on the quality and shelf-life of minimally processed peaches. The processing procedure consisted of washing, sanitization, peeling and stone removal. To remove the stone, the fruit was cut longitudinally, and three types of products were obtained, including halves, quarters and one-eighth segments. The fruit pieces were immersed in 2% ascorbic acid for 3 min and were packed in rigid polystyrene trays (Meiwa© M-54) coated with 14 μm PVC film (Omnifilm) (about 200 g per pack). The pieces were stored at 65% RH at 3, 6 or 9°C for 12 days, and were evaluated every four days. The appearance, fresh mass loss, color, O2 and CO2 concentration, acidity, total soluble solids, total and soluble pectin content and ascorbic acid concentration were measured. Minimally processed peaches stored at 3°C maintained higher quality due to control of ripening and senescence Moreover, an interaction effect between one-eighth segments and a temperature of 3°C was observed, and fruit with a superior appearance and higher soluble solids content was obtained.

Storage of strawberries (Fragaria ananassa L.) cv. ‘Oso Grande’, subjected to 1-MCP

This study aimed to investigate the influence of 1 - methylcyclopropene (1-MCP) on the substances involved in the softening of strawberry, cultivar Oso Grande, stored at room temperature, from the municipality of Itutinga, State of Minas Gerais. The parameters evaluated were: firmness, total pectin, percentage of solubilization, activities of the enzymes pectinmethylesterase (PME) (EC 3.1.1.11) and polygalacturonase (PG) (EC 3.2.1.15). It was concluded that 1-MCP delayed the softening of the fruits, since the fruits that were treated with 1-MCP after storage, have shown greater firmness, lower activities of PG and PME, and lower contents of total pectin, soluble pectin and percentage of solubilization.

Micronisation and hot air roasting of cowpeas as pretreatments to control the development of hard‐to‐cook phenomenon

Cowpeas stored under conditions of high temperature and high relative humidity (HTHH) develop the hard-to-cook (HTC) defect. Cowpeas with HTC defect require long cooking times, limiting their utilisation. Heat pretreatments are aimed at inactivating the enzymes responsible for HTC defect development. In this study, two heat pretreatments, micronisation and hot air roasting, were evaluated to assess their effectiveness in controlling the HTC defect development in cowpeas after storage under HTHH conditions. Micronisation and hot air roasting as pretreatments reduced the cooking time of cowpeas after storage under HTHH conditions compared with the control. The differences in the effectiveness of HTC defect control between micronisation and roasting were dependent on the degree of phytase inactivation on day 0. Phytase activity was reduced by 45 and 70% by roasting and micronisation pretreatments respectively. Reduced phytase activity was associated with higher phytate and soluble pectin contents in micronised cowpeas than in roasted cowpeas after HTHH storage. This observation is in agreement with the phytase-phytate-pectin theory. Micronisation was more effective than hot air roasting in controlling the development of HTC defect. This was due to a higher degree of phytase inactivation in micronisation when compared with roasting.

Multivariate analysis of fresh-cut carambola slices stored under different temperatures

Quality of fresh-cut carambola ( Averrhoa carambola L.) is related to many chemical and biochemical variables especially those involved with softening and browning, both influenced by storage temperature. To study these effects, a multivariate analysis was used to evaluate slices packaged in vacuum-sealed polyolefin bags, and stored at 2.5 °C, 5 °C and 10 °C, for up to 16 d. The quality of slices at each temperature was correlated with the duration of storage, O 2 and CO 2 concentration in the package, physical chemical constituents, and activity of enzymes involved in softening (PG) and browning (PPO) metabolism. Three quality groups were identified by hierarchical cluster analysis, and the classification of the components within each of these groups was obtained from a principal component analysis (PCA). The characterization of samples by PCA clearly distinguished acceptable and non-acceptable slices. According to PCA, acceptable slices presented higher ascorbic acid content, greater hue angles (° h) and final lightness (L-5) in the first principal component (PC1). On the other hand, non-acceptable slices presented higher total pectin content, PPO activity in the PC1. Non-acceptable slices also presented higher soluble pectin content, increased pectin solubilisation and higher CO 2 concentration in the second principal component (PC2) whereas acceptable slices showed lower total sugar content. The hierarchical cluster and PCA analyses were useful for discriminating the quality of slices stored at different temperatures.

Physicochemical and molecular analysis of cell wall metabolism between two navel oranges (Citrus sinensis) with different mastication traits

FJ72-1 navel orange and its bud mutant FJWC exhibit differences in melting texture character which are influenced mostly by cell wall metabolism. Here we compared the contents of water soluble pectin (WSP), protopectin, total pectin (TP), cellulose, and hemicellulose, activities of polygalaturonase (PG), pectin methylesterase (PME), pectate lyases (PL), cellulase (Cel) and gene expression levels of PG, PME, PL and Cel between the two cultivars. The content of cellulose and hemicellulose decreased progressively during fruit ripening. At the harvest time (230 DAF), the content of cellulose and hemicellulose in FJWC were obviously higher than those in FJ72-1; the WSP content, PG activities and its gene expression level in FJWC was lower than those in FJ72-1. Moreover, gene expression levels of PME and Cel in FJWC were only one-quarter of those in FJ72-1 at 230 DAF. The present work showed that the inferior melting character of FJWC attributed to the lower WSP, higher TP or protopectins, higher cellulose and hemicellulose than those in the pulp of FJ72-1 at harvest time. Lower expression levels of PG, PME and Cel at harvest time might be associated with the inferior melting character.

Cellular wall metabolism in citrus fruit pericarp and its relation to creasing fruit rate

Citrus creasing results in serious economic loss in many citrus orchards. Based on the different incidence of creasing, two sweet orange cultivars ‘Hong Jiang’ (grafting chimaera of which flesh is mostly from Citrus reticulata Blanco and peel is from Citrus sinensis Osbeck in) and ‘An Liu’ ( Citrus sinensis Osbeck) were used to investigate the creasing rate. The ultrastructure in cellular wall, cellular wall component, cellular wall degradation-related enzymes and expansin ( Ct-Exp1) of sweet orange during fruit ripening in field were comparatively analyzed. ‘Hong Jiang’ sweet orange had a higher creasing rate than ‘An Liu’ during ripening. The activities of polygalacturonase, cellulase and pectinesterase in cellular wall of ‘Hong Jiang’ increased more markedly compared with ‘An Liu’. The increases in the content of soluble pectin, ionically associated pectin, covalently bound pectin, hemicellulose and cellulose of ‘Hong Jiang’ were higher than those of ‘An Liu’. Furthermore, the enhanced degradation of the ultrastructure in the albedo cellular walls was observed in ‘Hong Jiang’. Moreover, the northern blot analysis indicated that the Ct-Exp1 gene expressed more strongly in peel of ‘Hong Jiang’ than ‘An Liu’ during fruit ripening. These data suggest that enhanced loss of pectin and cellulose in the cellular walls of peel tissue of sweet orange could result in fruit creasing.

Effects of 1-methylcyclopropene on apricot fruit quality, decay, and on physiological and biochemical metabolism during shelf-life following long-term cold storage

SummaryMature green apricot (Prunus armeniaca L. ‘Shanhuangxing’) fruit were exposed to 1-methylcyclopropene (1-MCP) at 0, 0.5, 1.0, or 5.0 µl l−1 for 12 h, or treated with 1.0 µl l−1 1-MCP for 0, 6, 12, or 24 h, stored at 0µC and 85 – 95% RH for 4 weeks, then transferred to a shelf-life simulation at 23µC and 80 – 90% RH. The shelf-life of apricots was effectively extended for > 2 d by pre-storage 1-MCP treatment at 1.0 or 5.0 µl l−1 for 6 h and/or 12 h. The decline in firmness, colour change, and the incidence of fruit decay were substantially inhibited by 1-MCP at 1.0 or 5.0 µl l–1 for 6 h and/or 12 h during cold storage and subsequent shelf-life. Increases in soluble pectin contents and decreases in ascorbic acid contents were delayed, but the levels of total phenolic compounds and flavonoids increased in 1-MCP-treated fruit during shelf-life. 1-MCP treatment enhanced the peroxidase activity of apricot fruit for 3 d during shelf-life, but inhibited ethylene production in harvested apricot fruit. These results support an effective application of 1-MCP to maintain apricot fruit quality and to extend the time for marketing.

고추냉이가 배추김치의 발효 중 이화학적 특성에 미치는 영향

본 연구는 고추냉이 뿌리(이하 고추냉이)가 배추김치의 발효와 저장성에 미치는 영향을 알아보고, 배추김치의 저장성 향상을 위한 천연 첨가제로서의 고추냉이의 이용 가능성을 모색하고자 하였다. 배추 무게에 대하여 0, 2, 3, 4, 5%를 첨가하여 배추김치를 담그어 10oC에서 35일간 발효시키면서 이화학적 특성을 살펴보았다. 발효 전반적으로 0% 처리구가 가장 낮은 pH를 보였고, 고추냉이 첨가량이 증가할수록 pH가 높았다. 또한 고추냉이 첨가량이 증가할수록 적숙기의 pH를 오랫동안 유지하였다. 총산은 발효 초기부터 말기까지 0% 처리구의 가장 높았고, 고추냉이 첨가량이 증가 할수록 낮은 총산을 보여 고추냉이 첨가가 배추김치의 발효를 지연시켜 주었다. 특히 3% 이상 첨가할 경우 발효를 지연시켜 주는 효과가 있음을 알 수 있었다. 총비타민 C 함량은 발효가 진행됨에 따라 증가하다 0%와 2% 처리구는 발효 8일, 3%, 4%와 5% 처리구는 발효 10일에 최대값을 보인 후 감소하였다. 담금 직후부터 발효 말기까지 고추냉이 첨가량이 증가할수록 총비타민 C 함량이 높았고, 특히 3% 이상 첨가한 처리구에서 더욱 높았다. 3% 이상 첨가한 처리구가 0%와 2% 처리구에 비해 총비타민 C가 최대 함량을 보인 후 완만하게 감소하여 발효가 지연되었다. 고추냉이 첨가량이 증가할수록 환원당 함량은 높았고, 발효 전반적으로 0%와 2% 처리구가 급격하게 감소하여 발효가 빨리 진행됨을 알 수 있었다. 반면 3% 이상 첨가한 경우 완만하게 환원당이 감소하였고, 발효 말기에도 높은 함량을 유지하였다. 수용성 펙틴의 경우 배추김치가 익어감에 따라 모든 처리구에서 점차로 증가하였고, 고추냉이 첨가량이 증가할수록 수용성 펙틴의 함량은 낮았다. 발효 말기로 갈수록 3% 이상 첨가한 처리구가 0%와 2% 처리구에 비해 더욱 낮은 값을 보였고, 고추냉이 첨가량이 증가할수록 수용성 펙틴의 증가하는 폭이 감소하여 발효가 서서히 진행을 알 수 있었다. 이상의 결과로 볼 때 고추냉이를 첨가할 경우 배추김치의 발효를 지연시켜 저장성을 향상시켜 주었고, 특히 3% 이상 첨가할 경우 바람직한 효과를 보였다. 따라서 배추김치를 담글 때 고추냉이를 첨가하게 되면 품질과 저장성을 향상시켜줄 것으로 기대된다.

Changes in pectic substances and cell wall hydrolase enzymes of mangosteen (Garcinia mangostana) fruit during storage

Mangosteen (Garcinia mangostana) fruits at mature green stage with 5% red spotting were held at room temperature (31–35°C, 84 ± 2% relative humidity (RH)) and at the storage temperature of 13°C (90 ± 2% RH). Firmness, pectin content, and activities of pectin methylesterase and polygalacturonase in the pulp (aril) were monitored every 2 days. Pulp firmness rapidly decreased at room temperature from day 0 to day 4 after storage and slightly decreased thereafter, whereas pulp firmness slowly decreased at 13°C. Water soluble pectin content in pulp increased more rapidly at room temperature than at 13°C. Insoluble pectin content in pulp decreased throughout the storage time at both storage conditions. Both pectin methylesterase and polygalacturonase activities in pulp increased more rapidly at room temperature than at 13°C. Changes in water soluble pectin and cell wall hydrolase enzymes in relation to pulp softening of mangosteen fruits are discussed.

Characterising polysaccharides in cherimoya (Annona cherimola Mill.) purée and their enzymatic liquefaction

Polysaccharides isolated in the alcohol-insoluble residues (AIR) from cherimoya (Annona cherimola Mill.) were characterised for contents of soluble pectin, cellulose, hemicellulose and lignin, and the distribution of neutral sugars and uronides in water-soluble pectin (WSP) and water-insoluble AIR (WAIR) fractions. For WSP, the predominant neutral sugar was arabinose and, for WAIR, cellulosic glucose and xylose. Two enzyme preparations were tested for their capacity to release neutral sugars and uronides from WAIR. The optimal incubation temperature (45 °C) and the most effective preparation—rich in pectinase, cellulase and xylanase activities—were selected according to a central composite rotatable design (CCRD). Enzyme was also applied to native cherimoya puree according to another CCRD, varying the enzyme concentration and incubation time. Native puree exhibited strong shear-thinning behaviour with high, extrapolated, yield stress. During enzymatic treatment, behaviour was less shear thinning, and yield stress, consistency index and Bostwick consistency tended to decrease, giving rise to purees of different rheological properties.

Effects of two pre-harvest calcium treatments on physiological and quality parameters in ‘Vogue’ cherries during storage

SummaryThe effects of two pre-harvest spray treatments with calcium chloride (CaCl2) concentrations up to 58.5 mM on physiological and quality parameters were investigated in ‘Vogue’ cherries during storage from 1 – 23 d in air at 1° – 3.5°C, at 85 – 95% RH, in two experimental years. No foliar or fruit toxicity was observed. Ca-treated fruit showed greater firmness, lower soluble pectin content, more resistance to stem removal, and less stem browning than watersprayed control fruit during storage. Ca spraying had no effect on fruit weight, fruit size, pH, titratable acidity, total soluble solids, Mg content, or peel colour; whereas there was an increase in Ca content and inconsistent changes in malic acid concentrations in fruits measured after 1 d in storage. Ca did not affect carbon dioxide (CO2) production rates, and showed only slight effects on the already low ethylene production rates, and on the low 1-aminocyclopropane-1-carboxylic acid (ACC) content during storage. In conclusion, treatment with 45 mM CaCl2 had positive effects on most of the quality parameters measured, with no negative effect under our particular experimental conditions.

Mudanças relacionadas ao amaciamento da graviola durante a maturação pós-colheita

Este trabalho teve por objetivo avaliar mudanças físicas, químicas e bioquímicas relacionadas ao amaciamento de graviola (Annona muricata L.) Crioula durante a maturação. Os frutos foram colhidos no estádio de maturidade fisiológica, em plantas cultivadas na Estação Experimental da Embrapa Agroindústria Tropical, em Pacajus, Ceará, armazenados a 26,3±0,6 ºC e 88±12% de umidade relativa, durante 1, 2, 3, 4 e 5 dias. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições. As variáveis analisadas foram: perda de massa, amido, pectina total e solúvel, e atividades das enzimas amilase, pectinametilesterase, poligalacturonase, alfa-galactosidases e beta-galactosidases. Não houve variação significativa no conteúdo de pectina solúvel. Após cinco dias, a perda de massa atingiu 5%, mas não promoveu murcha dos frutos. As reduções nos conteúdos de amido e de pectina total coincidiram com período de expressiva atividade, respectivamente, das enzimas amilase e da poligalacturonase e beta-galactosidase de parede celular. As modificações mais acentuadas no conteúdo de amido, de pectina total, na solubilização de pectinas e na atividade das enzimas amilase, pectinametilesterase, poligalacturonase e beta-galactosidase de parede celular ocorreram no período do segundo ao quarto dia após a colheita.

High-pressure treatment of cloudy apple juice

A factorial design with four factors (pressure, holding time, temperature and waiting period between crushing of apple and high-pressure (HP) treatment) was built up to study the effect of HP treatment on pectin methylesterase activity (PME, EC 3.1.1.11) in cloudy apple juice. PME activity was measured by the methanol release during the storage of samples at 4 °C for 1 month. Only the holding time of the treatment and three interactions between factors (holding time×temperature, pressure×waiting and holding time×waiting) had significant effects on the PME level. Increasing the pressure or the holding time at moderate temperatures (15–40 °C) increased the activity. PME purified from apple was pressure stable in the range 100–600 MPa at 25 °C. The soluble pectin content was not changed after HP treatment. The particles size increased with the temperature reached during the treatment, in agreement with a diffusion-limited-aggregation model but were independent of pressure and holding time. In a separate experiment we found a positive correlation between the PME activity and the residual content of the catechins suggesting that polyphenoloxidase (PPO, EC 1.14.18.1) and oxidized polyphenols play a role in the PME activity level after HP treatment.

Evaluation of pectin constituents of Japanese pear by near infrared spectroscopy

Japanese pears ( Pyrus serotina Rehder var. culta ‘Housui’) collected in 1997 and 1998 were measured for their pectin constituents including alcohol insoluble solids, water soluble pectin, oxalate soluble pectin, non-soluble pectin and total pectin. Near infrared (NIR) spectra (1100–2500 nm) were measured within the range of at 2 nm intervals. The NIR spectra of intact Japanese pear were measured by fiber optics in interactance mode and the spectra of juice were measured by diffuse trans-reflectance. The spectral data used were raw spectra and their second derivative. By using multiple linear regression, calibration equations developed from the intact fruit spectra and juice spectra, the alcohol insoluble solids in the fresh weight (AIS in the FW) and the oxalate soluble pectin content in the alcohol insoluble solids (OSP in the AIS) were accurately predicted (For intact fruit spectra: R = 0.93, SEP = 0.62 for AIS in the FW, and R = 0.95, SEP = 8.48 for OSP in the AIS; For juice spectra: R = 0.93, SEP = 0.63 for AIS in the FW and R = 0.91, SEP = 7.93 for OSP in the FW). In addition, the equations from the juice spectra could be used to predict the water soluble pectin in the alcohol insoluble solids (WSP in the AIS), and the total pectin in the alcohol insoluble solids (TP in the AIS) ( R = 0.91, SEP = 1.41 for WSP in the AIS and R = 0.94, SEP = 11.52 for TP in the AIS). The NIR models developed with the data collected in 1998 were not able to predict the 1997 data. This study showed that near infrared spectroscopy has potential to measure the pectin constituents of the Japanese pear.