鹿蹄草浸提液常温保鲜草莓的试验研究

将鹿蹄草浸提液添加到涂膜液中,对新鲜草莓进行处理,常温保藏并对其品质指标的变化进行测定。结果表明,该处理可减轻草莓中的可溶性固形物、Vc和总酸在贮藏过程中的降低幅度,减缓果实的失重。同时能显著抑制微生物的繁殖,使得草莓的腐烂程度降低,延长了草莓的保质期。     

鹿蹄草浸提液常温保鲜草莓的试验研究

本试验将鹿蹄草浸提液添加到涂膜液中,对新鲜草莓进行处理,常温保藏并对其品质指标的变化进行测定。结果表明,该处理可减轻草莓中的可溶性固形物、微生物C和总酸在贮藏过程中的降低幅度,减缓果实的失重;同时能显著抑制微生物的繁殖,使得草莓的腐烂程度降低,延长了草莓的保质期。     

香辛料抑菌活性研究及其在草莓保鲜中的应用

本实验揭示了一些香辛料提取液具有明显的抑制根霉等真菌的作用。将其添加到涂膜液中中对新鲜草莓进行处理，冷藏并对草莓品质指标的变化进行测定。结果表明，该处理可以抑制呼吸、减少Vc等营养物质的损耗，同时有效减少贮藏期间烂果率的发生，延长草莓的货架期。     

壳聚糖-有机酸复合物常温下对草莓保鲜的作用研究

壳聚糖在一定条件下与有机酸生成具有一定粘度的壳聚糖-有机酸复合物,在常温下将其涂膜新鲜草莓后,果实表面形成一层光滑、透明的可食用膜,能有效降低草莓的失水率、延缓草莓衰老过程,同时,还能减少草莓腐烂率,通过实验得出结论：经1.25%酒石酸配制1.25%壳聚糖涂膜液处理后的草莓在常温（22～24℃）下贮藏2 d后,果实品质与鲜果几乎无差别;贮藏5 d后,好果率仍达到80.2%.     

热处理与贮藏温度对草莓果实保鲜效果的影响

以大棚新鲜草莓为实验材料,分别研究2种热处理方式(40℃热空气,15min和40℃无菌水,15min)以及不同贮藏温度(常温20℃和低温4℃)对草莓的腐烂率、失重率的影响。结果表明,热处理明显有利于草莓的保鲜,其中热空气处理优于热水处理,低温贮藏优于常温贮藏。基于这一结论后,又以相同的新鲜草莓为实验材料,研究3种不同温度(35、40、45℃)的热空气和不同时间(10、15、20min)处理对草莓色泽、气味、硬度、酸度、糖含量以及呼吸强度的影响。结果表明,热处理能明显影响草莓贮藏期的生理和品质,热处理可保持草莓贮藏过程中的色泽、气味、硬度,降低其呼吸强度,减少草莓果实中糖和酸的损失,延缓草莓衰老。其中以45℃热空气处理10min保鲜效果最好。     

壳聚糖保鲜草莓效果的研究

草莓采后用壳聚糖醋酸溶液处理后，放在代温（４－１５℃）环境中贮藏，观察其外观品质的变化情况，并定期取样测定草莓的品质指标，贮藏７天后取出置于常温环境中，观察其货架期霉变情况，结果表明壳聚糖处理的草莓，硬度显著大于对照，ＶＣ含量降低比对照慢，花青素含量亦低于对照；壳聚糖处理可减少果实的腐烂和霉变，延称货架期。     

香辛料提取物保鲜草莓研究

香辛料提取液有一定的抑菌的功效,丁香的乙醇提取液对根霉、青霉、酵母菌、枯草芽孢杆菌均有良好的抑菌功效,尤其对根霉有明显的抑制作用.可明显的减缓草莓的呼吸强度,减少Vc、可溶性固形物、总酸等营养物质的损耗,显著延缓果实在贮藏期间的品质降低,提高草莓的货架保存期.     

壳聚糖复合涂膜对草莓保鲜的影响

迷迭香提取物、CaCl2、亚硫酸钠分别与壳聚糖复配涂膜研究草莓的贮藏保鲜技术,通过测定贮藏过程中草莓果实的营养成分、感官品质等指标,探究草莓在低温冷藏条件下的成熟衰老过程和不同保鲜剂处理对草莓贮藏品质的影响。结果表明:壳聚糖复配迷迭香提取物和壳聚糖复合CaCl2涂膜保鲜液均可显著地(P<0.05)减缓草莓的可溶性固形物、可滴定酸、Vc、还原糖含量的下降,抑制草莓细胞膜渗透率变化和果实的腐烂软化,保持草莓的硬度等贮藏品质。亚硫酸钠-壳聚糖处理可维持草莓的还原糖含量,延缓可滴定酸和Vc含量的下降。其中,1.5%壳聚糖+0.3%迷迭香提取物溶液浸渍涂膜5 min保鲜草莓效果最好,1.5%壳聚糖+2.0%CaCl2溶液浸渍涂膜5 min次之。     

草莓微冻保鲜方法的研究

采用微冻技术对草莓贮藏保鲜进行了研究。对草莓在贮藏过程中生理生化状况的分析表明，微冻保鲜技术在抑制草莓的呼吸作用、减缓营养物质的分解和保持草莓新鲜度等方面的效果显著。草莓的保鲜时间可达两个月以上，且品质与鲜果无明显差异。     

氧化淀粉的抑菌效果及草莓涂膜保鲜应用

本实验采用抑菌圈法研究氧化淀粉（oxidized starch,OST）的抑菌作用,通过测定草莓的质量损失率、腐烂率、菌落总数等理化指标研究OST对草莓的保鲜效果。结果表明：OST对常见致病菌金黄色葡萄球菌、大肠杆菌和常见草莓腐败菌青霉菌均具有明显的抑菌效果,OST中羧基相对含量越高则抑菌能力越强,其中羧基相对含量达57%的OST（OST-57）对金黄色葡萄球菌、大肠杆菌和青霉菌形成的抑菌圈直径分别为（29.00±0.87）、（28.00±1.73）、（15.75±0.65）mm;与未经处理草莓相比,OST-57对草莓的涂膜处理能够有效抑制菌落总数增长,显著降低草莓质量损失率和腐烂率（P＜0.05）,延缓草莓成熟过程中硬度和咀嚼性的变化,同时能够显著维持可溶性固形物和花色苷等营养物质含量（P＜0.05）。结论：OST-57浸泡涂膜处理能够更有效地延缓草莓果实的成熟衰老,可作为新型的果蔬涂膜材料,对于果蔬的采后保鲜具有应用价值。     

中草药醇提物抑菌筛选及对草莓保鲜效果的研究

采用菌丝生长速率法筛选出对草莓采后主要病原菌抑制效果最佳的中草药单剂及复配组合,并以腐烂率为调查指标,通过正交试验研究确定复配的最佳保鲜质量浓度配比,即丁香和蛇床子均为1g/L、补骨脂1.5g/L。使用中草药复合保鲜剂、丁香单剂、化学保鲜剂对草莓进行防腐保鲜处理,调查不同处理对草莓常温贮藏过程中各种保鲜指标的影响。结果表明：各保鲜剂处理组均能降低草莓贮藏过程中的质量损失率和腐烂率,减少可溶性固形物及VC含量的下降,且复合中草药处理组的各种保鲜指标均优于丁香单剂和化学防腐保鲜剂多菌灵。     

Methyl jasmonate treatment of strawberry fruits enhances antioxidant activity and the inhibition of nitrite production in LPS-stimulated Raw 264.7 cells

The effect of methyl jasmonate postharvest application on the antioxidant and anti-inflammatory activity of strawberry fruits was evaluated. Results showed that the methyl jasmonate treated strawberry extract had higher antioxidant activity and suppresses the nitrite production in LPS-stimulated RAW 264.7 murine macrophages. The HPLC profiles of both treated and untreated strawberry extracts were compared. To evaluate which compounds are responsible of these higher activities it was also investigated the antioxidant and anti-inflammatory capacities of the hexane, chloroform, EtOAc, and n-butanol fractions obtained from the methyl jasmonate treated strawberry. The EtOAc and n-butanol fractions exhibited the most potent antioxidant activity compared to the hexane and chloroform fractions. In addition the n-butanol fraction was able to decrease nitrite production. The EtOAc and n-butanol fractions were analyzed by LC–MS. These results showed that methyl jasmonate promotes antioxidant and anti-inflammatory capacity of strawberry fruits by the stimulation of phenolic compounds and anthocyanins production.     

壳聚糖复合涂膜常温保鲜草莓的研究

采用菌丝生长速率法筛选出对草莓采后主要病原菌抑制效果最佳的中草药复合物,并将其与涂膜剂壳聚糖、助剂抗坏血酸(VC)、抗氧化剂植酸复配成复合保鲜剂,通过正交实验确定了各组分的最佳浓度配比:复合中草药提取物0.3%(丁香、蛇床子、补骨脂的质量比为1:1:1)、壳聚糖1.25%、VC1.25%、植酸0.05%。草莓经此复合保鲜液处理后,显著降低了常温贮藏期间的失重率、腐烂率,延缓了可溶性固形物、VC和可滴定酸含量的下降,且各项保鲜指标均优于1.25%壳聚糖的单独涂膜处理。     

葡萄、芒果、草莓乙醇提取物抗氧化活性组分分析及其抗氧化相互作用

利用高效液相色谱-质谱联用技术分析3种水果(葡萄、芒果、草莓)乙醇提取物的主要组成成分。建立2种体外抗氧化模型:1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)和2,2’-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS),比较3种不同水果提取物在不同抗氧化模型中相互作用的能力。同时,利用等辐射分析法,分析以不同比例混合后,各物质之间抗氧化相互作用的差异。结果表明:葡萄提取物的总酚以及总黄酮含量最高,其次是草莓和芒果。草莓提取物中主要含有鞣花酸、花葵素-3-葡糖苷、花葵素-3-乙酰葡糖苷和花葵素-3-芸香苷等。芒果提取物主要含有鞣花酸、芒果苷和桑橙素等。葡萄提取物中主要含有反-白藜芦醇、花色苷等。同一组合,在不同抗氧化模型中表现出的活性不同,葡萄提取物体外抗氧化性较强,其次是芒果和草莓。同一模型中,抗氧化协同率最高的组合比例为草莓-芒果1∶9(DPPH模型)和草莓-芒果1∶1(ABTS模型)。     

Effect of surface waxes on the persistence of chlorpyrifos-methyl in apples, strawberries and grapefruits

The effects of the cuticle and epicuticular waxes of grapefruit, strawberry and apple on the photodegradation and penetration of chlorpyrifos-methyl were studied. Photodegradation experiments were conducted by exposing the insecticide to the light of a xenon lamp in the presence of a film of wax extracted from the fruit surface. The half-life of chlorpyrifos-methyl irradiated in absence of waxes was 9.6 min. The half-lives of pesticide irradiated in the presence of wax extracts of apple, grapefruit and strawberry were 83, 34 and 26 min, respectively. In penetration studies, fruit with and without wax layers were treated with an aqueous suspension of pesticide. The penetration of the pesticide from the cuticle to the pulp was measured after 24 h. Samples without wax contained a higher total amount of insecticide than those with wax. No pesticide was detected in samples of apple and grapefruit pulp. Residues were detected in all fractions of strawberry. The waxes and cuticle appear to have some effect on the photodegradation and penetration of chlorpyrifos-methyl in fruit samples.     

Nutritional and nutraceutical comparison of Jamaican Psidium cattleianum (strawberry guava) and Psidium guajava (common guava) fruits

Psidium cattleianum (strawberry guava) is one of many underutilised edible fruits that grow wild in Jamaica, and could potentially be commercially exploited to yield health and economic benefits. In this study, the total phenolics, proximate contents, and antioxidant, anti-inflammatory, and antimicrobial activities of P. cattleianum and P. guajava (common guava), a well-known species, were compared. Strawberry guavas were found to be superior to common guavas in antioxidant and antimicrobial activities, total phenolics and vitamin C content. They also possessed relatively high fibre content (24.9%). The hexane and ethyl acetate extracts of strawberry guavas showed cyclooxygenase-2 enzyme inhibitory activities of 18.3% and 26.5%, respectively (250 μg/mL), indicating anti-inflammatory activity. The EtOAc and MeOH extracts of P. guajava showed 56.4% (COX-2) and 44.1% (COX-1) inhibitory activity, respectively. Additionally, nine compounds were isolated from strawberry guava fruits, some of which demonstrated anti-inflammatory activity. These results indicate that strawberry guavas are beneficial for health.     

Development of Active Films From Pectin and Fruit Extracts: Light Protection,Antioxidant Capacity,and Compounds Stability

Pectin films containing fruit extracts were developed and tested in relation to ultraviolet light transmission, phytochemical contents, and antioxidant capacity during 90 d shelf life storage. Aqueous and alcoholic extracts from 5 different fruits (acerola, cashew apple, papaya, pequi, and strawberry) were obtained. Because the alcoholic extracts from acerola, cashew apple, and strawberry presented the highest phytochemical content and antioxidant capacity, they were incorporated into pectin films individually or as a mixture. Incorporation of these extracts into pectin films provided antioxidant capacity while retaining the physical properties. The pectin films containing fruit extract acted as adequate light barrier and prevented photooxidation. Among the prepared films, the pectin film containing acerola extract afforded the highest antioxidant capacity, with a half‐life of 99 d. Overall, the results revealed that incorporation of fruit extracts into pectin films potentially produces antioxidant films and coatings for different food applications.     

Comparison of phenolic composition and antioxidant properties of two native Chilean and one domestic strawberry genotypes

The phenolic composition of extracts from the forms chiloensis and patagonica of Fragaria chiloensis were compared with that of the commercial strawberry Fragaria × ananassa cv. Chandler by high performance liquid chromatography with diode-array detector (HPLC–DAD) and high performance liquid chromatography with electrospray ionization mass spectroscopy detector (HPLC–ESI–MS). The phenolic constituents in the three species were mainly proanthocyanidins, hydrolysable tannins, anthocyanins and flavonol glycosides. In both native strawberry species the main flavonol glycoside was quercetin 3-O-glucuronide and the minor anthocyanins identified were cyanidin-malonyl-glucoside and pelargonidin-malonyl-glucoside. The highest anthocyanin content was found in the commercial red strawberry while ellagic acid was the main phenolic in the native white strawberry. From the methanolic fruit extract of the native Chilean strawberry Fragaria chiloensis ssp. chiloensis f. chiloensis four known antioxidants were isolated by selective fractionation using the bleaching of the free radical scavenger 1,1-diphenyl-2-picrylhydrazyl (DPPH) as the guiding assay. The antioxidant properties (measured as the bleaching of the DPPH radical) were determined for methanol extracts of the three fruits, for fractions of F. chiloensis ssp. chiloensis f. chiloensis, and for the isolated compounds cyanidin-3-glucoside, pelargonidin-3-glucoside, quercetin-3-glucuronide and ellagic acid. This study allows a clear chemical differentiation between the commercial strawberry and the Chilean white strawberry.