减压冷藏对芒果贮藏品质的影响

以台农一号芒果为试验材料,研究了减压条件对其采后贮藏品质的影响。结果表明:减压冷藏技术能够有效地减缓果实中可滴定酸、VC以及可溶性固形物含量的降低,且保持了芒果的硬度,对其黄化以及膜透性的增加具有良好的抑制作用。其中,10,20 kPa下芒果的贮藏品质明显优于30kPa的;10kPa下的芒果可以保持较低的转黄指数和较高的硬度;20kPa下的芒果能更好地维持VC、有机酸等营养物质。实际生产中,兼顾贮藏效果和贮藏成本,选择20kPa的压力较为适宜。     

河套地区不同品种小麦品质特性研究

以在河套地区种植的10个不同麦区主推的小麦品种为研究对象,探究小麦籽粒、小麦粉和面团基本特性。结果表明：其中有4个品种的6项指标都达到我国小麦品种品质分类标准中强筋小麦品种要求。小麦籽粒的面筋含量、沉降值与小麦粉的蛋白质含量、水分含量、形成时间、稳定时间、粉质指数呈极显著正相关关系(P<0.01),小麦籽粒的蛋白质含量、形变能量与小麦粉的湿面筋含量、水分含量、形成时间、最大拉伸阻力、能量、最大拉伸比呈显著正相关(P<0.05)。根据方差累计贡献率提取出4个主成分可以反映原变量92.899%的小麦品质特性综合信息,可为河套地区优质小麦品种的筛选、培育及不同品种小麦的深加工提供参考。     

不同品种李子品质特性及其酿酒适宜性评价

为筛选李子果酒发酵的适宜品种,本研究以四川省主栽和新选育的7个李子品种为研究对象,采用理化分析、顶空固相萃取-气相色谱-质谱（Headspace Solid Phase Microextraction Gas Chromatography-Mass Spectrometry,HS-SPME-GC-MS）技术结合差异显著性分析和偏最小二乘判别分析（Orthogonal Partial least Squares-Discriminant Analysis,OPLS-DA）分析了7个品种的基本理化特性,全面分析比较7个品种发酵李子酒的品质。结果表明,7个品种李果实的品质表现出丰富的多样性,其中紫皇（ZH）和大石早生（DS）具有可溶性固形物（SSC）、多酚和黄酮含量高等优点,是酿造高品质李子酒的佳选原料。通过对7个品种李子发酵果酒品质比较可知,ZH和DS发酵果酒抗氧化能力、干浸出物（>52.08 g/L）和酒精度（>14.03%vol）均显著高于其它五个品种（P<0.05）,且挥发性风味物质丰富,其中ZH酒体中酯类、醇类和萜烯类化合物含量丰富,赋予其显著的果香和花香特征,DS酒体中特征香气物质为庚酸乙酯、叔丁基丙二酸酯、1-庚醇和橙花醇等,李子典型香气好。此外,在感官评价中ZH和DS这2个品种,在香气、滋味和口感方面评分较高,表明ZH和DS两个品种适宜于李子果酒发酵,该研究为李子酒适酿品种的选择和栽培提供理论依据。     

石家庄地区10个小麦品种理化特性及其面条品质研究

以石家庄地区种植的10个小麦品种为研究对象,通过测定小麦粉物化指标和面条品质指标并进行相关性分析,以探究其物化品质及其对面条品质的影响和相关性。结果表明,冀麦U80、藁优2018、冀麦765及中麦886四种小麦粉品质较好,其制作的面条具有较好的质地和口感。通过相关性分析可知,蛋白质含量与湿面筋含量呈显著正相关（P<0.05）,小麦粉持水力、吸水率与面条吸水率呈极显著正相关（P<0.01）,面团形成时间、稳定时间与面条质构指标及感官评价呈显著或极显著正相关,弱化度与面条品质呈显著负相关（P>0.05）,面条感官评价与峰值粘度、衰减值,面条硬度、内聚性、咀嚼性,L*值、a*值、白度呈显著或极显著正相关。该研究可为石家庄地区小麦加工利用提供一定的理论参考。     

不同品种青稞全粉品质特性

为明确青稞全粉的营养及理化特性,为青稞全粉的加工与利用提供依据,该文以来自青海的6个青稞品种为研究对象,对不同品种青稞全粉的营养成分、粒径、颗粒结构特性、水合特性、吸油性、糊化特性、热特性和抗氧化特性进行比较。结果表明,青稞全粉颗粒为椭圆形和球形,呈现A型和V型结晶结构。昆仑14的淀粉含量（66.53%）、直链淀粉含量（16.96%）最高,全粉粒径（112.95μm）、崩解值（226.00 cP）最小,在加工贮藏中具有良好的凝胶稳定性;昆仑15的脂肪含量（2.68%）最低,回生值（1 214.00 cP）最大,凝胶回生性强,可以作凝胶类产品;昆仑17的蛋白质含量（11.86%）、脂肪含量（3.09%）、膳食纤维含量（21.56%）最高,水溶性指数（22.43 g/100 g）最大;昆仑19的β-葡聚糖含量（4.36%）最高;肚里黄吸水性（7.61 g/g）、吸油性（1.38 g/g）最强,适合应用于油炸食品和脂肪类食品中。昆仑14的总酚含量和总黄酮含量最高,其抗氧化能力最强,不同品种青稞全粉的品质特性存在差异。     

不同品种蓝莓品质特性及聚类分析

通过对山东省14 个主栽蓝莓品种的感官品质、营养品质、加工品质等指标进行测定,并采用聚类分析法评价蓝莓品种的综合品质,从而筛选出品质较佳的蓝莓品种。结果表明：不同品种蓝莓品质存在差异,以抗氧化物质含量、出汁率、固酸比差异较大。品种‘L5’花色苷含量最高（617.46 mg/100 g）且固酸比最大（47.78%）;‘蓝塔1’出汁率最高（78.43%）;‘蓝塔2’总糖含量最高（10.75%）。14 个品种可聚为5 类,第1类为‘37-1’、‘奥尼尔’、‘北陆’和‘B’;第2类为‘埃利奥特1’、‘布尔吉塔’、‘蓝丰’及‘蓝塔1’;第3类包括‘埃利奥特2’、‘杜克’和‘Z’;‘H34’和‘蓝塔2’聚为第4类;‘L5’为第5类。经分析初步评价,第2类为适宜加工果汁果酒的优良品种;第3类为适宜贮藏的蓝莓品种;第4类为适宜鲜食的优良品种;第5类为加工果酱、果脯的优良品种。     

不同品种芒果果脯和果干的品质比较分析

以金煌芒、桂七、台农和玉芒等四种不同品种的芒果为原料,采用色差计、电子舌、电子鼻及气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）等仪器,分别从色泽、滋味、气味及挥发性风味物质四方面评价不同芒果品种对果脯和果干原果风味及品质的影响。结果表明：金煌芒果脯、台农果脯、玉芒果脯较好地保留了原果色泽;金煌芒果干、桂七果脯、桂七果干、台农果干、玉芒果脯、玉芒果干较好地保留了原果滋味;基于电子鼻的PCA分析发现,台农果脯、台农果干较好地保留了原果的气味,其次是玉芒果脯、玉芒果干;不同品种芒果鲜果、果脯和果干鉴定出的主要挥发性风味成分有醇类、酯类、酮类、烷烃、烯烃、芳香烃及其他物质,其中烯烃类是主要的挥发性风味化合物,玉芒果脯、玉芒果干的烯烃相对含量均较高,分别为81.09%、77.52%。金煌芒果脯、金煌芒果干、桂七果干、玉芒果脯、玉芒果干较好地保留了原果的挥发性风味物质。综合考量,认为玉芒芒果最适合开发原果风味芒果果脯及果干。     

6个品种李果实品质差异性分析

目的 探寻蜂糖李、珠宝李、红李、江安李、青红脆李和酥李6个不同品种李果实之间品质的特征和差异性。方法 利用液相色谱法、氨基酸分析仪法、分光光度法以及滴定法等方法分析李果实中的营养成分并进行了不同李果实的品质分析。结果 李果实的可溶性糖含量主要由果糖、葡萄糖和蔗糖组成, 其中葡萄糖含量最高, 其次是果糖或蔗糖; 蜂糖李的可溶性糖总量、总糖含量、可溶性固形物、甜度值和糖酸比均显著高于其他品种, 这可能是其口感更甜的主要原因; 有机酸方面, 苹果酸是主要的有机酸, 占总量的88%以上, 其中珠宝李的苹果酸含量最高, 青红脆李的总酸含量最高; 氨基酸分析显示, 天冬氨酸和脯氨酸含量较高, 珠宝李的游离氨基酸总量最高; 总黄酮和维生素C含量最高的为青红脆李, 而维生素E含量最高的为红李。结论 6个李品种李果实品质具有显著性差异, 本研究为不同李果的品质资源利用和李水果精品战略提供了理论依据和实践指导。     

基于主成分分析和HS-SPME-GC-MS技术综合评价不同品种芒果品质特性

为表征台农、象牙和金煌三种芒果的品质特性,本文通过测定其主要品质指标,利用主成分分析法(PCA),构建芒果主要品质综合评分模型,并采用HS-SPME-GC-MS技术对其挥发性风味物质进行分析,综合评价其品质。结果表明,金煌的可溶性固形物、总糖含量和糖酸比最高,分别为19%、24.18 mg/g和10.86;台农的V_C和总酚含量最高,分别达9.52 mg/100 g和1.03 mg/g;主成分分析结果表明,台农的综合得分最高,其次为金煌,象牙的综合得分最低。HS-SPME-GC-MS技术从三种芒果中共检测出116种挥发性风味物质,主要包括烯烃类、酚类和醛类等8类物质。台农和象牙的挥发性化合物以烯烃类为主,相对含量分别为45.52%和58.12%,金煌中以酚类物质为主,相对含量为56.88%。通过ROAV分析法共确定了15种关键风味化合物,其中台农和象牙香气贡献最大的物质为(E,Z)-2,6-壬二烯醛,金煌香气贡献最大的是3-己烯醛。台农呈柑橘香、甜香等芳香气味,象牙具有黄瓜香特征风味,而金煌含有特殊的木香气味,该风味主要由2,4-二叔丁基苯酚所贡献。综合分析认为,台...     

不同品种西瓜常温贮藏期间品质变化及贮藏特性研究

以"京欣2号"和"京秀"西瓜为试材,研究西瓜常温贮藏期间品质和生理的变化以及不同品种之间的差异.结果表明:随着贮藏时间的延长,西瓜瓜皮不断变薄,质量损失增加,可溶性固形物减少,葡萄糖、果糖等主要营养物质也不断被消耗,但水分含量、可滴定酸含量变化甚微;京秀西瓜瓜皮变薄速率、质量损失、葡萄糖和果糖等营养物质消耗均比京欣2号...     

Reduction of chilling injury in ripe Alphonso mango fruit in cold storage by temperature conditioning

The influence of ripening temperature and cold conditioning of pre-climacteric fruits on the incidence of chilling injury (CI) in ripe mango fruits cv. Alphonso during refrigerated storage was investigated. Fruits previously held and ripened at tropical ambient temperature (AT, 27–34°C) developed CI (skin staining or browning) when ripe fruits were subsequently stored at 5, 10, or 15°C for shelf-life extension. Fruits held and ripened at 20°C1°C, RH 85–90% showed little evidence of CI when subsequently stored at 5 or 10°C up to 14 days. Chilling injury in ripe mangoes was also avoided by holding pre-climacteric fruits for a minimum period of 30 days at 10°C and then ripening them at 27–34°C. The quality of the ripe mangoes remained good during cold storage for 7 days and were acceptable until 10–14 days with minimal changes in texture, flesh colour, carotenoids, total soluble solids, titratable acids and ascorbic acid. Shelf-life of ripe mangoes can thus be extended under refrigeration by pre-storage conditioning.     

Resistance of industrial mango peel waste to pectin degradation prior to by‐product drying

Susceptibility of industrial mango peel waste to pectin degradation during storage at ambient conditions (25 °C, 63% relative humidity) for up to 5 h before by‐product stabilisation by drying was explored. Depending on the interim storage period in the wet state, pectins were recovered from the dried peels by hot‐acid extraction. Most important, pectin degradation during the temporary storage of the wet peels was insignificant, as revealed by yields, composition, average molecular properties, and techno‐functional quality. Hardly acetylated (DAc 2.5–4.5%), rapid‐set high‐methoxyl pectins were obtained at starch‐corrected net yields of 14.1–15.6 g hg^?1. Irrelevant de‐esterification during peel storage in the wet state was confirmed by overall uniform setting temperatures. Arabinogalactans, uniformly indicated by high molar galactose/rhamnose ratios of 13.8–16.9 mol/mol and an arabinose percentage of 9.5–14.4 mol hmol^?1 of galactose residues, affected the galacturonide contents, intrinsic viscosities, and gel strengths throughout. The wet peels, derived from widespread manual peeling in mango canning, tolerated intermediate storage for 5 h, thus facilitating by‐product stabilisation on smaller scales.     

采收成熟度对台农芒果贮藏品质的影响

研究了60%和80%2种采收成熟度对不同后熟条件下(自然成熟、促进成熟和抑制成熟)台农芒果贮藏品质的影响。结果表明:与对照(自然成熟)相比,使用乙烯利处理台农芒果果实,加速了2种成熟度果实的成熟进程,而使用热处理结合乙烯吸收剂处理则具有明显的延缓病害发生和果实软化,抑制可溶性糖积累、有机酸和Vc降解的作用。在同一种后熟条件下(自然成熟、促进成熟和抑制成熟的任何一种),60%成熟度的果实其品质变化慢于80%成熟度的果实,但其风味品质却差于80%成熟度的果实。     

芒果热处理对贮藏品质影响及机理研究

以芒果为原材料,研究热处理(50、55、60、65、70℃)对芒果常温贮藏品质的影响,筛选最佳的处理条件,并探讨其机理。结果表明,合适的热处理能够抑制芒果贮藏期间呼吸强度、转黄率、多酚氧化酶和过氧化物酶活性的上升,延缓果实硬度、Vc含量、好果率等指标下降,保持较好的品质。最佳的热处理条件为50℃-10min、60℃-1min和70℃-5s。     

A study of factors affecting in-situ De-esterification of mango (Mangifera indica) pectin

De-esterification of mango peel pectin in situ by the action of the enzyme pectinesterase (PE) has been investigated. The rate of enzymic deesterification was highest between pH 8.5 and 9.5 with chemical deesterification also being important. In-situ PE activity declined with fruit ripening but remained relatively constant when assayed on citrus pectin. The most likely explanation for this difference is a change in suitability of the pectin substrate within the fruit during ripening. A reduction in the degree of esterification (DE) of the pectin to 36-42% was obtained following incubation of the mango peels at pH 8.5 for 90 min. A crude preparation of exogenous PE from mango peel and lime pulp was incubated at pH 8.5 with heat-treated (PE inactive) peel as a means of increasing the rate and extent of de-esterification. The PE activity of both these exogenous enzyme preparations was lower on the peel than that of the in-situ mango enzyme, but considerably higher on a hot-water-soluble fraction extracted from the peel. It is suggested that enzyme solubility and pectin accessibility are the major factors affecting in-situ de-esterification of pectin in mango peel.     

环境温度对"紫花"芒果后熟及感官品质的影响

以0.1%的乙烯利处理"紫花"芒果(Mangifera indica cv.Zihua),研究环境温度对其后熟进程和感官品质的影响。结果表明:30℃促进了芒果的后熟进程,第4d果实达到完熟,而在20℃条件下需要6d;20℃贮运环境有利于芒果果皮叶绿素降解,表现为其果皮h值降低,果实均匀饱满,果肉可溶性固形物升高,保持合适的糖酸比,口感较佳。在20℃催熟芒果中检测出36种呈香物质,并含有更多种类的醇、酮、酯等芳香物质,高于30℃催熟芒果的26种。综合比较后熟芒果的感官品质指标,20℃贮运环境促进了催熟芒果的内源生化反应,更有利于芒果后熟。     

Phenolic compounds and antioxidant capacity of Brazilian mango (Mangifera indica L.) varieties

Phenolic compounds and antioxidant activities of four mango varieties cultivated in Brazil were analyzed. The profile of flavonol-O-glycosides and xanthone-C-glycosides was characterized in pulps from Haden, Tommy Atkins, Palmer, and Ubá cultivars and in the agro-industrial residues from Ubá variety by LC–ESI–MS analysis. The first three varieties were collected from conventional production, whereas Ubá was obtained from organic production. The total phenolic content of the peels and seed kernel extracts was analyzed utilizing Folin-Ciocalteu’s reagent. The aqueous-methanolic extracts of pulp, peel and seed kernels were analyzed for antioxidant activity (AA) by free radical-scavenging and reducing power. A total of 12 flavonoids and xanthones were identified in the pulps, peels and seed kernels, with larger amounts of these compounds being present in the organically grown Ubá variety. The Ubá mango pulp presented higher AA and the peel and seed kernel extracts showed higher AA than did a commercial standard.     

5种杂柑果实品质及制汁适应性的研究

对5个杂柑品种果实品质及制汁性能进行了研究,结果表明果汁的可溶性固形物含量变化范围为12.8%~14.2%,平均为13.7%;可滴定酸含量变化范围为0.51%~0.84%,平均为0.69%;出汁率变化范围为46.3%~57.8%,平均为52.5%,出汁率顺序为天草>南香>宫内伊予柑>诺瓦>甜桔柚。综合评价,天草和南香的出汁率、可溶性固形物及可滴定酸、还原糖指标均比较高,果汁风味浓郁,且果汁滋味和香气品评分数较高,是制汁的理想品种。     

Physiological and biochemical changes of different fresh-cut mango cultivars stored at 5 °C

Treatments to inhibit browning, decay and to extend shelf life of ‘Keitt’, ‘Kent’ and ‘Ataulfo’ mango cultivars as a fresh‐cut produce were investigated. Combinations of calcium chloride (CaCl₂), antioxidants [ascorbic acid (AA), citric acid (CA)] and two commercial film coatings resulted in a reduction of browning and deterioration of fresh‐cut mangoes stored at 5 °C, especially for the Ataulfo cultivar. The use of CaCl₂ + AA + CA significantly reduced colour deterioration, loss of firmness and did not affect sensory characteristics of fresh‐cut mango, with a larger effect in the Ataulfo cultivar. In general, these treatments prevented loss of sugar and vitamin C of cubes during storage at 5 °C. Shelf life of this cultivar was 21 days, while that of Keitt and Kent was only 9 and 12 days, respectively. There is a correlation between carotene and vitamin C content of Ataulfo mango and its longer shelf life compared with the other cultivars.     

Utilization of mango peels as a source of pectin and polyphenolics

Two different options for the combined recovery of pectin and phenolic compounds from mango peels, a byproduct of industrial mango processing, were developed. After extraction of dried mango peels with diluted sulfuric acid, the phenolic compounds were adsorbed using a styrene–divinylbenzene copolymerisate resin, and pectin was obtained from the effluent by precipitation with ethanol. Phenolic compounds were recovered from the resin with methanol and the eluate was lyophilized (Process I). Alternatively, the pectin was precipitated by adding the crude extract to ethanol. After removal of the organic solvent, the phenolic compounds were obtained from the aqueous phase of the precipitation bath using the adsorbent resin as described before (Process II). While in total, 129.4 mg/g polyphenols were detected in the lyophilizate obtained from Process I, only 71.0 mg/g dm could be recoverd from Process II. The profiles of the polyphenols were almost identical, revealing that during pectin precipitation preferential adsorption of polyphenolic compounds to the pectin may be excluded. Besides the characterization of the pectins and the phenolic compounds, investigations into the influence of the drying temperature on the polyphenolic content of the peels were carried out, indicating a significant loss of flavonol glycosides depending on heat exposure. On the other hand, some xanthone glycosides were formed during the drying process. Furthermore, antioxidative capacities of the lyophilized eluates were investigated using the DPPH, TEAC and FRAP assays. The antioxidative capacity of the extracts exceeded that of mangiferin and quercetin 3-O-glucoside, respectively, thus demonstrating mango peels to be a suitable source of health-beneficial compounds. The lyophilizates obtained from Process I showed higher antioxidative capacities in all three assays. These findings indicate a correlation between the amount of phenolic compounds and the antioxidative capacity.

Industrial relevance

Byproducts of mango processing amount to 35–60% of the total fruit weight. Their complete exploitation for further product recovery is a promising measure from both an environmental and economic point of view. In our previous study mango peels were found to be a rich source of pectin, with a high degree of esterification and phenolic compounds, like flavonol O- and xanthone C-glycosides. Therefore, two alternative processes for the combined recovery of pectin and polyphenols, which can easily be integrated in an existing pectin production process, were developed in the present study.