Nepal produces large quantity of mandarin (Citrus reticulata Blanco) annually but faces big losses due to improper postharvest treatments. The experiment was carried out during 2012-2013 with the objective of assessin...Nepal produces large quantity of mandarin (Citrus reticulata Blanco) annually but faces big losses due to improper postharvest treatments. The experiment was carried out during 2012-2013 with the objective of assessing the effect of different postharvest treatments on quality and shelf life of mandarin. The postharvest treatments were: wax emulsion at 10%, bavistin at 0.1%, wax at 10% with bavistin at 0.1%, calcium chloride at 1%, Jeevatu at 5% along with untreated fruits as a control. The experiment was conducted for four weeks of storage at ambient condition in Nepal Agricultural Research Council, Khumaltar, Kathmandu. Wax in combination with bavistin was found as the most effective in reducing the physiological loss in weight, whereas bavistin proved to reduce decay loss up to four weeks of storage. The fruits treated with wax alone and with combination of bavistin retained maximum firmness, juice percentage, vitamin C and palatability rating during the storage. The minimum total soluble solid and maximum titrable acidity were recorded in the fruits treated with wax plus bavistin. The present findings indicate that mandarin can be stored up to four weeks when treated with wax as well as wax with bavistin in the condition with 14°C - 18°C temperature and 45% - 73% relative humidity.展开更多
Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective market...Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective marketing.This study aimed to inspect the effects of Gibberellic Acid(GA_(3))and Salicylic Acid(SA)postharvest treatments on retaining the high quality of Khalal Barhi fruits during controlled atmosphere storage.Fresh samples of Barhi fruits at Khalal stage harvested at three different ripening levels were dipped after harvesting in GA3(150 ppm)or SA(2.0 mmol/L)and subsequently stored in controlled atmosphere(0°С,5%O_(2),5%CO_(2),80%±5%RH).The results revealed that the GA_(3) and SA treatments reduced the percentage of weight loss and decay in the fruits,while the total soluble solids increased.Moreover,GA_(3) and SA treatments were significantly efficient in limiting the changes in fruit color and texture of Barhi dates compared to the control.Sensorial results support the experimental data and disclosed that the GA_(3)(150 ppm)treatment in the controlled atmosphere(CA)storage was better in conserving the quality of Barhi at the Khalal maturity stage and delaying ripening process.展开更多
Polygalacturonase inhibiting proteins(PGIPs)are plant proteins involved in the inhibition of polygalacturonases(PGs),cell-wall degrading enzymes often secreted by phytopathogenic fungi.Previously,we confirmed that PGI...Polygalacturonase inhibiting proteins(PGIPs)are plant proteins involved in the inhibition of polygalacturonases(PGs),cell-wall degrading enzymes often secreted by phytopathogenic fungi.Previously,we confirmed that PGIP2 from Phaseolus vulgaris(PvPGIP2)can inhibit the growth of Aspergillus niger and Botrytis cinerea on agar plate.In this study,we further validated the feasibility of using PGIP as an environmental and ecological friendly agent to prevent fungal infection post-harvest.We found that application of either purified PGIP(full length PvPGIP2 or truncated tPvPGIP2_5-8),or PGIP-secreting Saccharomyces cerevisiae strains can effectively inhibit fungal growth and necrotic lesions on tobacco leaf.We also examined the effective amount and thermostability of PGIP when applied on plants.A concentration of 0.75 mg/mL or higher can significantly reduce the area of B.cinerea lesions.The activity of full-length PvPGIPs is not affected after incubation at various temperatures ranging from20 to 42◦C for 24 h,while truncated tPvPGIP2_5-8 lost some efficacy after incubation at 42◦C.Furthermore,we have also examined the efficacy of PGIP on tomato fruit.When the purified PvPGIP2 proteins were applied to tomato fruit inoculated with B.cinerea at a concentration of roughly 1.0 mg/mL,disease inci-dence and area of disease had reduced by more than half compared to the controls without PGIP treatment.This study explores the potential of PGIPs as exogenously applied,eco-friendly fungal control agents on fruit and vegetables post-harvest.展开更多
【目的】探讨采后不同处理方式对杏鲍菇贮藏品质及抗氧化酶系统的影响,为杏鲍菇贮藏保鲜技术的应用与发展提供理论指导。【方法】以新鲜采收的杏鲍菇为试验材料,分别采用0.03 mm的聚乙烯(PE)薄膜袋封口包装、0.05 mm的PE薄膜袋封口包装...【目的】探讨采后不同处理方式对杏鲍菇贮藏品质及抗氧化酶系统的影响,为杏鲍菇贮藏保鲜技术的应用与发展提供理论指导。【方法】以新鲜采收的杏鲍菇为试验材料,分别采用0.03 mm的聚乙烯(PE)薄膜袋封口包装、0.05 mm的PE薄膜袋封口包装和1.5%壳聚糖涂膜3种处理,以0.05 mm PE保鲜袋不封口为对照,于4℃、相对湿度85%—95%的条件下贮藏,通过测定失重率、色差值、硬度、可溶性固形物(TSS)、还原糖及可溶性蛋白质含量等理化指标,以及过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)等3种抗氧化酶活性以及相对电导率、丙二醛(MDA)、超氧阴离子()、过氧化氢(H2O2)的含量,研究不同采后处理方式对杏鲍菇贮藏品质及抗氧化酶系统的影响。【结果】与PE不封口处理相比,两种厚度的PE保鲜袋处理能显著降低杏鲍菇子实体失重率(P<0.01),在贮藏18 d时,两种处理的失重率仅为0.35%和0.20%;两种PE处理的菇体硬度显著高于对照(P<0.05),且在贮藏期间两种处理均分别在第3天和第12天出现了两个硬度峰值;PE处理不易发生褐变,但在贮藏末期,0.03 mm PE处理的褐变程度显著增加(P<0.05)。两种PE处理均能显著抑制贮藏期间TSS和可溶性蛋白的增加,减缓还原糖的消耗。1.5%壳聚糖涂膜处理在0—9 d菇体硬度显著增加(P<0.05),随后硬度快速下降;其失重率较高,与对照无显著差异(P>0.05);贮藏期间褐变指数低,但在贮藏末期的褐变程度显著(P<0.05);贮藏的中期与后期,TSS、还原糖和可溶性蛋白含量的变化均显著低于对照。3种处理在一定程度上提高了杏鲍菇的抗氧化能力,与对照处理相比,3种处理均能显著降低膜透性和脂膜过氧化产物MDA的含量(P<0.05),但在贮藏中、后期,壳聚糖处理的电导率和MDA含量均显著高于两种PE处理。0.03 mm PE和1.5%壳聚糖涂膜处理能显著降低超氧阴离子产生速率和过氧化氢的含量(P<0.05),0.05 mm PE处理能显著降低过氧化氢的含量(P<0.05),但其超氧阴离子产生速率则在3—12 d内显著高于对照(P<0.05);在贮藏前期与末期,3种处理均具有较高的POD活性和CAT活性(P<0.05),但在整个贮藏期间,SOD的活性变化与对照无明显差异(P>0.05)。【结论】在整个贮藏过程中PE处理表现出较好的贮藏效果;其中0.05 mm PE包装处理效果更为明显,有效保持了杏鲍菇的品质。展开更多
文摘Nepal produces large quantity of mandarin (Citrus reticulata Blanco) annually but faces big losses due to improper postharvest treatments. The experiment was carried out during 2012-2013 with the objective of assessing the effect of different postharvest treatments on quality and shelf life of mandarin. The postharvest treatments were: wax emulsion at 10%, bavistin at 0.1%, wax at 10% with bavistin at 0.1%, calcium chloride at 1%, Jeevatu at 5% along with untreated fruits as a control. The experiment was conducted for four weeks of storage at ambient condition in Nepal Agricultural Research Council, Khumaltar, Kathmandu. Wax in combination with bavistin was found as the most effective in reducing the physiological loss in weight, whereas bavistin proved to reduce decay loss up to four weeks of storage. The fruits treated with wax alone and with combination of bavistin retained maximum firmness, juice percentage, vitamin C and palatability rating during the storage. The minimum total soluble solid and maximum titrable acidity were recorded in the fruits treated with wax plus bavistin. The present findings indicate that mandarin can be stored up to four weeks when treated with wax as well as wax with bavistin in the condition with 14°C - 18°C temperature and 45% - 73% relative humidity.
文摘Barhi dates at Khalal maturity stage are well-known with their pleasant taste,crispy texture,and bright yellow color.It is necessary to extend the duration of Barhi Khalal stage which is too short for effective marketing.This study aimed to inspect the effects of Gibberellic Acid(GA_(3))and Salicylic Acid(SA)postharvest treatments on retaining the high quality of Khalal Barhi fruits during controlled atmosphere storage.Fresh samples of Barhi fruits at Khalal stage harvested at three different ripening levels were dipped after harvesting in GA3(150 ppm)or SA(2.0 mmol/L)and subsequently stored in controlled atmosphere(0°С,5%O_(2),5%CO_(2),80%±5%RH).The results revealed that the GA_(3) and SA treatments reduced the percentage of weight loss and decay in the fruits,while the total soluble solids increased.Moreover,GA_(3) and SA treatments were significantly efficient in limiting the changes in fruit color and texture of Barhi dates compared to the control.Sensorial results support the experimental data and disclosed that the GA_(3)(150 ppm)treatment in the controlled atmosphere(CA)storage was better in conserving the quality of Barhi at the Khalal maturity stage and delaying ripening process.
文摘Polygalacturonase inhibiting proteins(PGIPs)are plant proteins involved in the inhibition of polygalacturonases(PGs),cell-wall degrading enzymes often secreted by phytopathogenic fungi.Previously,we confirmed that PGIP2 from Phaseolus vulgaris(PvPGIP2)can inhibit the growth of Aspergillus niger and Botrytis cinerea on agar plate.In this study,we further validated the feasibility of using PGIP as an environmental and ecological friendly agent to prevent fungal infection post-harvest.We found that application of either purified PGIP(full length PvPGIP2 or truncated tPvPGIP2_5-8),or PGIP-secreting Saccharomyces cerevisiae strains can effectively inhibit fungal growth and necrotic lesions on tobacco leaf.We also examined the effective amount and thermostability of PGIP when applied on plants.A concentration of 0.75 mg/mL or higher can significantly reduce the area of B.cinerea lesions.The activity of full-length PvPGIPs is not affected after incubation at various temperatures ranging from20 to 42◦C for 24 h,while truncated tPvPGIP2_5-8 lost some efficacy after incubation at 42◦C.Furthermore,we have also examined the efficacy of PGIP on tomato fruit.When the purified PvPGIP2 proteins were applied to tomato fruit inoculated with B.cinerea at a concentration of roughly 1.0 mg/mL,disease inci-dence and area of disease had reduced by more than half compared to the controls without PGIP treatment.This study explores the potential of PGIPs as exogenously applied,eco-friendly fungal control agents on fruit and vegetables post-harvest.
文摘【目的】探讨采后不同处理方式对杏鲍菇贮藏品质及抗氧化酶系统的影响,为杏鲍菇贮藏保鲜技术的应用与发展提供理论指导。【方法】以新鲜采收的杏鲍菇为试验材料,分别采用0.03 mm的聚乙烯(PE)薄膜袋封口包装、0.05 mm的PE薄膜袋封口包装和1.5%壳聚糖涂膜3种处理,以0.05 mm PE保鲜袋不封口为对照,于4℃、相对湿度85%—95%的条件下贮藏,通过测定失重率、色差值、硬度、可溶性固形物(TSS)、还原糖及可溶性蛋白质含量等理化指标,以及过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)等3种抗氧化酶活性以及相对电导率、丙二醛(MDA)、超氧阴离子()、过氧化氢(H2O2)的含量,研究不同采后处理方式对杏鲍菇贮藏品质及抗氧化酶系统的影响。【结果】与PE不封口处理相比,两种厚度的PE保鲜袋处理能显著降低杏鲍菇子实体失重率(P<0.01),在贮藏18 d时,两种处理的失重率仅为0.35%和0.20%;两种PE处理的菇体硬度显著高于对照(P<0.05),且在贮藏期间两种处理均分别在第3天和第12天出现了两个硬度峰值;PE处理不易发生褐变,但在贮藏末期,0.03 mm PE处理的褐变程度显著增加(P<0.05)。两种PE处理均能显著抑制贮藏期间TSS和可溶性蛋白的增加,减缓还原糖的消耗。1.5%壳聚糖涂膜处理在0—9 d菇体硬度显著增加(P<0.05),随后硬度快速下降;其失重率较高,与对照无显著差异(P>0.05);贮藏期间褐变指数低,但在贮藏末期的褐变程度显著(P<0.05);贮藏的中期与后期,TSS、还原糖和可溶性蛋白含量的变化均显著低于对照。3种处理在一定程度上提高了杏鲍菇的抗氧化能力,与对照处理相比,3种处理均能显著降低膜透性和脂膜过氧化产物MDA的含量(P<0.05),但在贮藏中、后期,壳聚糖处理的电导率和MDA含量均显著高于两种PE处理。0.03 mm PE和1.5%壳聚糖涂膜处理能显著降低超氧阴离子产生速率和过氧化氢的含量(P<0.05),0.05 mm PE处理能显著降低过氧化氢的含量(P<0.05),但其超氧阴离子产生速率则在3—12 d内显著高于对照(P<0.05);在贮藏前期与末期,3种处理均具有较高的POD活性和CAT活性(P<0.05),但在整个贮藏期间,SOD的活性变化与对照无明显差异(P>0.05)。【结论】在整个贮藏过程中PE处理表现出较好的贮藏效果;其中0.05 mm PE包装处理效果更为明显,有效保持了杏鲍菇的品质。
