Changes in strawberry phenolics, anthocyanins, and antioxidant capacity in response to high oxygen treatments

Changes in fruit quality, decay, phenolic and anthocyanin content, and antioxidant capacity of strawberries (Fragaria × ananassa Duch. cv. Allstar) stored under air and high oxygen atmospheres at 5 °C were investigated. Freshly harvested strawberries were placed in jars and ventilated continuously with air or with 40, 60, 80, or 100 kPa O₂ at 5 °C for up to 14 days. Samples were taken initially, and after 3, 7, 10 and 14 days of storage. While fruit quality parameters such as titratable acidity, total soluble solids and surface color were only slightly affected by differing levels of O₂, the higher oxygen concentration treatments significantly reduced decay. Oxygen concentrations higher than 60 kPa also promoted increases in ORAC values, total phenolics and total anthocyanins as well as individual phenolic compounds analysed by HPLC during the initial 7 days of storage. However, this effect diminished with prolonged storage. No significant differences in ORAC values, total phenolics, total anthocyanins, or the individual phenolic compounds were observed among the high O₂ and air-stored fruits after 14 days of storage. These results indicate that high oxygen treatments exert the most effects on fruit quality and antioxidant capacity of strawberry fruit in the first 7 days of storage.     

Antioxidant phytochemical and fruit quality changes in mango (Mangifera indica L.) following hot water immersion and controlled atmosphere storage

Tropical fruits such as mangoes destined for import into the United States are commonly required to have a thermal treatment against invasive pests, which could be combined with controlled atmosphere (CA) storage to prolong shelf life and preserve fruit quality. Changes in antioxidant phytochemicals and resultant quality during storage and ripening were investigated in fresh mangoes, as influenced by application of CA in combination with a hot water immersion quarantine treatment (46 °C for 75 min). Mature-green mangoes with or without a hot water treatment, were held in air, 3% O₂ + 97% N₂, or 3% O₂ + 10% CO₂ + 87% N₂ and evaluated for external quality and phytochemical differences after storage for 2 weeks at 10 °C and after subsequent ripening in air at 25 °C. Visible appearance of anthracnose during ripening was effectively inhibited by the hot water treatments combined with CA. Concentrations of gallic acid and numerous hydrolysable tannins and their resultant antioxidant capacity were unaffected by the hot water treatment, while total polyphenolics naturally decreased throughout fruit ripening, regardless of hot water treatment or storage atmosphere. However, the overall decline in polyphenolic concentration was inhibited by the CA treatments, as a result of delayed ripening. Quality parameters such as flesh colour and titratable acidity provided supporting evidence that the CA conditions helped to delay fruit ripening.     

不同保鲜剂对蓝莓保鲜效果的比较

为了延长蓝莓的贮藏期,本研究以蓝莓为原料,研究了丁香酚缓释保鲜、丁香提取液、乙醇熏蒸、气调保鲜、丁香酚缓释结合气调保鲜5种不同保鲜剂对其贮藏期品质的影响。结果显示,这5种保鲜剂能显著抑制蓝莓果实腐烂和质量损失率,有效缓解可溶性固形物、可滴定酸、还原糖、Vc含量的降低,抑制MDA含量的上升,同时,可使蓝莓果实保持较高的SOD活力。贮藏49 d时,经丁香酚缓释结合气调包装的蓝莓腐烂率和失重率分别为50.13%和2.71%,可溶性固形物、可滴定酸、还原糖、Vc、花色苷含量分别为7.06%、7.26 g/kg、4.14 g/100 g、0.93 g/100 g和117.48 mg/100 g,MDA含量为26.84 nmol/g,SOD活力为176.34 U/mL。与对照组相比,丁香酚缓释结合气调包装能延长蓝莓14 d贮藏期。结果表明,5种保鲜处理对蓝莓具有一定的保鲜作用,其中丁香酚缓释结合气调包装保鲜方式最好。     

Physicochemical changes in fresh-cut wax apple (Syzygium samarangenese [Blume] Merrill & L.M. Perry) during storage

Physicochemical changes, such as peel and flesh colours, total anthocyanin content, browning index, firmness, total soluble solid (TSS), titratable acidity (TA), sugar acid ratio (TSS/TA), antioxidant capacity, total phenolic content and ascorbic acid content, in fresh-cut Taaptimjan wax apple fruit stored at 4 ± 2 °C and 12 ± 2 °C for 7 days were investigated. The skin of fresh-cut fruit stored at 4 ± 2 °C showed higher a^∗ value, chroma and total anthocyanin content and lower hue angle than those stored at 12 ± 2 °C. Lightness (L^∗ value) and whiteness index of the fresh-cut fruit flesh stored at 12 ± 2 °C showed significantly lower than those stored at 4 ± 2 °C which related to an significant increase in browning index. Firmness, total soluble solid, titratable acidity and sugar acid ratio did not significant changes during storage. Antioxidant capacity and total phenolic content increased throughout storage. Ascorbic acid content of the fresh-cut fruit stored at 4 ± 2 °C remained constant throughout storage whilst ascorbic content at 12 ± 2 °C decreased and was lower than that at 4 ± 2 °C. At 4 ± 2 °C antioxidant capacity and ascorbic acid content were higher than that stored at 12 ± 2 °C whilst there was no significant difference in total phenolic content. In conclusion, the reduction of whiteness index and the increase in browning index of fresh-cut wax apple flesh were the key factors affecting its quality and storage at 4 ± 2 °C could reduce the change in the flesh colour and maintained the peel colour and nutritional values of fresh-cut wax apple fruit during storage.     

Fruit quality and physiological responses of litchi cultivar McLean's Red to 1-methylcyclopropene pre-treatment and controlled atmosphere storage conditions

The effect of 1-MCP pre-treatment and two different controlled atmosphere storage conditions (CA-1, 17% O₂ + 6% CO₂; CA-2, 7% O₂ + 3% CO₂) on fruit quality parameters and physiological changes with respect to pericarp browning in ‘McLean's Red’ litchi were investigated. Fruits were pre-treated with 1-MCP (500 nl/l) and held at CA-1 or CA-2 for 21 d at 2 °C and at 90% RH. Stand-alone CA-1 or stand-alone CA-2 and the commercially adopted sulphur dioxide (SO₂) treatment were included in this study for comparison. Of the five treatments 1-MCP + CA-1 was most effective in preventing browning, loss of red colour (colour value a*) of the pericarp, ascorbic acid content; and retaining acceptable SSC/TA and taste. Fruit from 1-MCP + CA-1 showed higher overall acceptance after 21 d storage without any off-flavour according to the sensory panel data.1-MCP + CA-1 reduced the polyphenol oxidase (PPO) and peroxidase (POD) activity, retained membrane integrity and anthocyanin content during storage. Although SO₂ treatment prevents browning it showed negative effects on SSC/TA, taste and membrane integrity. Stand-alone CA-2 condition indicated higher pericarp browning, PPO, POD activity and loss of membrane integrity. Therefore, 1-MCP pre-treatment and CA-1 retains overall fruit quality for up to 21 d.     

不同处理条件的蓝莓货架品质比较分析

通过对比不同处理蓝莓冰温贮藏后低温货架品质的差异,探求蓝莓采后保鲜的最佳处理。以‘莱克西’蓝莓为试材,采用箱式气调(MAP)、1-甲基环丙烯(1-MCP)、箱式气调结合1-甲基环丙烯(MAP+1-MCP)处理,对蓝莓品质指标、生理指标、硬度、色泽的影响。通过OPLS-DA分析得出处理间的差异性指标为花色苷、硬度。在货架期第12d时,MAP+1-MCP处理的蓝莓果实的可溶性固形物含量为12.84%、可滴定酸含量为0.85%、Vc含量为35.61 mg/100 g、花色苷含量为87.51 mg/100 g、硬度为897.75 g,与对照组相比,MAP+1-MCP处理的呼吸强度和乙烯生成速率分别下降了13.32%和28.27%。这表明MAP+1-MCP处理可以使果实Vc、花色苷、可滴定酸含量含量下降趋势得到延缓,减缓了蓝莓果实硬度的下降,延缓果实软化,同时还能抑制果实呼吸速率及乙烯生成速率的升高,但各组处理对蓝莓果实的色泽影响不显著。MAP+1-MCP是蓝莓果实采后的最佳处理,实验结果可以在蓝莓商品化销售中应用。     

1-MCP处理对磨盘柿减压贮藏品质及生理变化的影响

以磨盘柿为试材,通过对不同浓度1-甲基环丙烯(1-MCP)处理果实在减压冷藏期间主要生理生化指标、贮藏品质变化规律的分析,探讨了1-MCP处理对果实减压冷藏保鲜效果的影响。结果表明:1-MCP处理明显抑制了减压贮藏果实硬度、可溶性单宁含量的下降;同时也较好的抑制了果实可溶性固形物(去除单宁后)、丙二醛、膜相对透性和PPO活性的升高,并且能使果实在贮藏期间保持较高的SOD活性,但对可滴定酸含量的变化没有显著影响;减压贮藏果实适宜的1-MCP处理浓度为1.0μL/L。     

减压和1-MCP处理对蓝莓保鲜效果的影响

为探究减压保鲜和1-MCP在蓝莓保鲜上的应用,以东北"灿烂"蓝莓为试材,常压冷藏(4±1)℃为对照,3种处理:在(4±1)℃条件下,1.5k Pa减压处理21d;减压预处理12h;1-MCP处理,并常压冷藏至21d,探究4种处理的感官和生理指标的变化情况。结果表明:与对照比较,3种不同处理方式均能不同程度降低蓝莓的失重率和腐烂率,1.5k Pa预处理12h保鲜效果最好,其次是1-MCP处理,均优于超低压保鲜。相关性分析表明,蓝莓的腐烂率与失重率、呼吸强度呈正相关,而与TSS、总酚、黄酮、花青素等的含量及防御性酶SOD、CAT活性呈负相关。     

Effect of chitosan coatings on the physicochemical characteristics of Eksotika II papaya (Carica papaya L.) fruit during cold storage

The effect of chitosan on the physicochemical characteristics of Eksotika II papaya fruit stored at 12 ± 1 °C and 85–90% relative humidity, was investigated. Chitosan provided an effective control in reducing weight loss, maintained firmness, delayed changes in the peel colour and soluble solids concentration during 5 weeks of storage. The titratable acidity declined throughout the storage period, though at a slower rate in the chitosan coated fruit as compared to the control. Sensory evaluation results also confirmed the efficacy of chitosan. Consequently, the internal gaseous concentrations of CO₂ and O₂ also proved the usefulness of chitosan. These findings suggest that chitosan can be used commercially for prolonging the storage life of Eksotika II papaya fruit.     

1-甲基环丙烯结合膜气调处理对河口香蕉贮藏品质的影响

以云南河口香蕉为试验材料,将不同质量浓度(0.00,0.08,0.16,0.32 g/L)的1-甲基环丙烯(1-MCP)结合PBI气调保鲜袋、微孔膜包装河口香蕉,并于15 ℃下恒温贮藏,研究贮藏期间香蕉可溶性固形物、硬度、病情指数、转黄指数、POD酶(过氧化物酶)、失重率、呼吸强度、可滴定酸的变化规律.结果表明:1-M...     

The Effect of 1-Methylcyclopropene (1-MCP) on Quality and Cell Wall Hydrolases Activities of Fresh-Cut Muskmelon (Cucumis melo var reticulatus L.) During Storage

The effects of 1-methylcyclopropene (1-MCP) on quality and cell wall hydrolases activities changes in fresh-cut muskmelon fruit stored at 4?±?1 °C for 7 days were investigated. The results showed that ethylene production of the fresh-cut fruit remained constant during refrigerated storage. 1-MCP treatments delayed the loss of fresh weight and the increase in electrolyte leakage and maintained the firmness of the fresh-cut fruit. The best results are showed in the fresh-cut fruit treated with 1.0 μL L^?1 1-MCP. The use of 1-MCP had no influence on the total soluble solids (TSS) content and pH of the fresh-cut fruit which they remained constant over storage. The titratable acidity (TA) of the fresh-cut fruit decreased during storage and the sample treated with 1.0 μL L^?1 1-MCP showed the lowest data. TSS/TA ratio increased during storage and the TSS/TA ratio was lower in 1-MCP-treated samples than that for the control one. The use of 1-MCP inhibited polygalacturonase (PG), β-galactosidase (β-Gal) and β-galactanase activities, whereas the increases in these enzymes activities were found in the control. Antioxidant capacity and total phenolics content of both 1-MCP-treated and untreated samples remained constant over storage. The reduction of total ascorbic acid content was detected after 7 days of storage. The ascorbic acid content in 1-MCP-treated sample was slightly higher, although not significantly different, than that of the control after 7 days. These results suggest that the loss of firmness was the key factor affecting quality of fresh-cut muskmelon fruit and the use of 1-MCP maintained the quality and inhibited the loss of firmness by retarding the increase in electrolyte leakage and inhibiting cell wall hydrolases activities.     

Combination of 1-methylcyclopropene treatment and controlled atmosphere storage retains overall fruit quality and bioactive compounds in mango

BACKGROUND: Postharvest application of fungicide prochloraz and hot‐water dip are commercially practiced to control postharvest diseases in mangoes. Owing to the increasing consumer demand for organically produced fruit, the search for natural environmentally friendly alternative products and processes has become important for the fruit industry. This study evaluated the combined effect of 1‐methylcyclopropene (1‐MCP) (500 nL L^?1) and controlled atmosphere storage conditions (CA‐1, 5% O₂ + 5% CO₂ or CA‐2, 3% O₂ + 8% CO₂) on the maintenance of fruit quality and bioactive compounds on hot‐water treated mangoes (cv. Kent) during postharvest storage. RESULTS: In comparison to the 1‐MCP + CA‐1 treatment, 1‐MCP + CA‐2 reduced the incidence of anthracnose, weight and firmness loss; delayed the skin and flesh colour development; prevented the increase of soluble solids concentration/titratable acidity ratio, ethanol and acetaldehyde content; and maintained the ascorbic acid, carotenoid, total phenolic and flavonoid contents, and antioxidant scavenging activity in hot‐water treated mangoes. The untrained panel preferred 1‐MCP + CA‐2 treated fruit to the fruit subjected to other postharvest treatments adopted in this investigation. CONCLUSION: Our investigation suggests that the combined effect of 1‐MCP and CA‐2 storage can be recommended as an alternative treatment to replace prochloraz application for hot‐water treated mangoes and can be adopted commercially for organic export markets. Copyright © 2011 Society of Chemical Industry     

1-MCP和真空包装对冰温贮藏磨盘柿品质的影响

为了探讨磨盘柿脱涩保脆新途径,研究了不同处理对柿果的贮藏品质、生理生化指标以及软化酶系的影响。结果表明:冰温(-0.5～-0.2℃)贮藏条件下,1-MCP可以有效抑制柿果硬度的下降、乙醇的积累、细胞膜透性的上升、可滴定酸的减少、PG和CX活性的增加;1-MCP结合真空包装不仅可以有效抑制柿果硬度的下降,还能促进可溶性单宁向不溶性单宁的转化,可溶性单宁在60 d下降为0.03%(完全脱涩),硬度为17.58 kg/cm2,贮藏期延长30 d。     

QUALITY OF FRESH-CUT TOMATOES

Tomato fruit at pink or light-red stages of ripening were cut into slices, rinsed with water containing 50 μL.L⁻¹ sodium hypochlorite and drained. They were stored in perforated polyethylene package at 1C in air or controlled atmosphere for five and ten days. Weight loss, chlorophyll and lycopene contents, seed discoloration, fungal infection, total soluble solids content, titratable acidity, sugar/acid ratio, pH, flavor and taste, firmness, ascorbic acid content, rate of respiration and ethylene production, and electrolyte leakage were evaluated after each storage period. The overall quality of controlled atmosphere-stored slices was better than that of air stored slices. Slices from light-red fruit had lower weight loss, minimum seed discoloration, lower     

1-MCP处理对苹果采后常温贮藏品质的影响

以‘红富士’和‘黄元帅’两个品种苹果为实验材料,研究1-甲基环丙烯（1-methylcyclopropene ,1-MCP）处理后苹果在20 ℃常温贮藏条件下果实品质的变化,探讨1-MCP对短期贮藏苹果品质的影响。结果表明,与对照相比,1 μL/L 1-MCP处理对‘红富士’和‘黄元帅’苹果的质量损失率、硬度及可溶性固形物含量无显著影响（P＞0.05）;处理组可滴定酸含量在7 d后显著高于对照组（P＜0.05）;‘红富士’苹果1-MCP处理在14 d后可以延缓pH值上升,而‘黄元帅’处理组7 d后即可延缓pH值升高;1-MCP处理对‘红富士’VC含量无显著影响（P＞0.05）,而‘黄元帅’中1-MCP组VC含量在第1天开始即显著高于对照组（P＜0.05）。由此可见,1-MCP处理对不同品种苹果不同品质指标的影响不同。     

1-MCP缓释处理对气调贮藏后的‘安久’梨货架期品质的影响

以‘安久’梨为试材,利用3% 1-甲基环丙烯（1-MCP）缓释剂处理在2.2% O₂下贮藏6个月后的两个果园梨果实,研究1-MCP缓释处理对梨果实出库后在冷藏（模拟运输过程）和货架期中果实生理病害发生、乙烯释放率、硬度、果皮叶绿素、可溶性固形物和可滴定酸的影响,为今后其商业标准化应用提供理论依据。结果表明:与对照组果实相比,1-MCP缓释处理能降低货架期果实腐烂率和虎皮病发病率,降低α-法尼烯含量和共轭三烯积累。此外,1-MCP缓释处理能抑制果实乙烯释放,延缓果实硬度下降,果皮叶绿素和可滴定酸降解,但对可溶性固形物含量无影响。1-MCP处理的Lot 375果园（海拔为114.30 m）梨果实在经冷藏10 d后第21 d货架期时果实硬度降至24.76 N并伴随乙烯逐渐上升,而1-MCP处理的Lot 39果园（海拔为10.06 m）梨果实果实硬度为39.14 N,此时乙烯仍维持在较低的水平。因此,在人工短缺时,晚采收的高海拔地区果园‘安久’梨可先进行气调贮藏,待出库、清洗、分拣、包装处理后加入缓释型1-MCP,可降低货架期果实生理病害发生,保持较高的果实品质,但不影响果实软化。     

Cold storage conditions affect the persistence of diphenylamine, folpet and imazalil residues in ‘Pink Lady’ apples

‘Pink Lady^®’ apples (Malus domestica) fruit were harvested at commercial maturity treated with three different agrochemical products, and stored at 1 °C under either air or controlled atmosphere conditions (2.5 kPa O₂ + 3 kPa CO₂ and 1 kPa O₂ + 2 kPa CO₂) for 15 and 28 weeks. Diphenylamine, folpet and imazalil contents in both skin and flesh were simultaneously determined after cold storage plus a simulated marketing period of 1 or 7 days at 20 °C. Results showed that apples stored in 2.5 kPa O₂ + 3 kPa CO₂ retained higher contents of diphenylamine residues in comparison with those stored in 1 kPa O₂ + 2 kPa CO₂ or refrigerated air. Significant differences in imazalil skin contents were found throughout the simulated marketing period at 20 °C after storage for 28 weeks in controlled atmospheres.     

Postharvest application of 1-Methylcyclopropene modulates fruit ripening, storage life and quality of 'Tegan Blue' Japanese plum kept in ambient and cold storage

The role of postharvest application of 1-Methylcyclopropene (1-MCP) in modulating 'Tegan Blue' Japanese plum fruit ripening and quality under ambient and cold storage conditions was investigated. 1-MCP-treated fruit (0, 0.5, 1.0 and 2.0 μL L⁻¹) were allowed to ripen at ambient temperature in Experiment 1, while in the second experiment the fruit were kept in cold storage (0, 3 and 6 weeks) before ripening. In both experiments, 1-MCP treatment significantly delayed (2–8 days), suppressed (30–70%) the climacteric ethylene production, maintained higher fruit firmness (34–60%), titratable acidity, L* , chroma, hue angle of fruit skin and pulp, and reduced concentrations of soluble solids, ascorbic acid, total carotenoids and total anti-oxidants as compared to the control. 1-MCP (1.0 μL L⁻¹) treatment suppresses and delays the climacteric ethylene production with acceptable fruit quality during ripening at ambient temperature and is effective in extending the storage life up to 6 weeks with minimal loss of plum fruit quality.     

The effect of postharvest 1-MCP treatment and storage atmosphere on ‘Cripps Pink’ apple phenolics and antioxidant activity

This study investigated the effect of a postharvest 1-methylcyclopropene (1-MCP) treatment, controlled atmosphere and storage time on the total antioxidant activity (TAA) and phenolic compounds in the peel and flesh of ‘Cripps Pink’ apples (Malus domestica Borkh.). Preclimacteric apples were harvested and treated with 1-MCP then stored in normal atmosphere (NA) or controlled atmosphere (CA) at 0 °C for up to 160 days. In general, the level of phenolics decreased by 9% in the peel and significantly increased twofold in the flesh during cold storage, regardless of storage atmosphere or 1-MCP treatment. However, treatment with 1-MCP resulted in significantly lower concentrations of chlorogenic acid and procyanidin B2 in apple flesh, and catechin and epicatechin in the peel compared to the control fruits. There was no significant effect of CA on the phenolic compounds during long-term storage, except for quercetin 3-galactoside and quercetin 3-glucoside, which both significantly increased under CA storage. Total antioxidant activity (TAA) is an important nutritional attribute of apples in the human diet. The results showed that TAA in the peel tissue was about eight times higher than that of the flesh, with mean values of 4.75 g TE/kg FW and 0.56 TE/kg FW, respectively. The TAA in both the peel and flesh tissue increased significantly during storage by 40% and 70%, respectively. The storage atmosphere did not significantly affect TAA in either the peel or flesh, whilst the 1-MCP treatment significantly reduced the TAA in the peel tissue only. These results show the beneficial combined effects of pre-storage 1-MCP treatment and CA on ‘Cripps Pink’ apple phenolic composition and antioxidant capacity during long term storage.     

Effect of 1-methylcyclopropene and/or chitosan coating treatments on storage life and quality maintenance of Indian jujube fruit

Indian jujube (Ziziphphus mauritina, cv. ‘Cuimi’) fruits were harvested at stage of mature-green and then treated with 1-methylcyclopropene (1-MCP) at two doses (0 and 600 nl l⁻¹) for 12 h at room temperature. Half of the fruits were coated with 1.5 g/100 ml of chitosan (CTS) solution after 1-MCP treatment and subsequently stored at room temperature and 80-90% relative humidity (RH). Results indicated that 600 nl l⁻¹ of 1-MCP, 1.5 g/100 ml of CTS or their combination were effective in terms of senescence inhibition during storage and compared to control, the storage life was extended by 7, 5 and 8 d, respectively. Fruits treated with the combination of 1-MCP and CTS coating showed better retention of chlorophyll content, total soluble solids, ascorbic acid and fruit firmness, delayed climacteric ethylene evolution and respiration rate, reduced stem-end rots incidence, decreased PG and LOX activities than those with other treatments. Coating alone reduced weight loss and stem-end rots incidence. It delayed the declining firmness and the onset of climacteric ethylene production and respiration rate, but did not influence the peak levels of ethylene and respiration rates. The treatment with only 1-MCP delayed the degreening process and suppressed PG and LOX activities through 10 d at room temperature. The results showed that the treatment with the combination of 1-MCP and CTS coating improved greatly the storage life extension and quality maintenance of Indian jujube fruit at room temperature storage.