柠檬酒的研究

柠檬酒是利用纯天然无公害柠檬果皮，用萃取法提取果皮中的维生素C等多种对人体有益的矿物质和有机酸，是一种老少皆宜的美容保健饮品。     

不同成熟阶段柠檬果皮挥发物和酚类成分分析

为探究柠檬果皮香气和酚类成分在不同成熟阶段的变化特点,以抗病品种香水柠檬和泰吹柠檬不同成熟阶段果皮为材料,采用顶空固相微萃取结合气相色谱-质谱法分析其挥发物成分,高效液相色谱法测定其酚类成分.结果表明:2个品种柠檬果皮中共检测到86种挥发性成分,以萜烯类、醛类和醇类为主,香水柠檬果皮中倍半萜和醛类含量较高,泰吹柠檬果皮...     

柠檬果皮精油挥发性成分的GC-MS分析

采用水蒸气蒸馏法(SD)与有机溶剂萃取法分别提取干、鲜柠檬果皮的精油,通过气相色谱和质谱联用仪测定了柠檬果皮精油的挥发性成分.结果显示:较简单的有机溶剂萃取法更有利于果皮精油挥发性成分的保留,依据化合物的质谱特性鉴定出柠檬果皮油里含有72种挥发性成分.柠檬果皮精油的主要成分为柠檬烯,含量在50%以上.     

鲜榨柠檬原汁对7种常见食源性致病菌抑菌效果及被膜形成的影响

目的研究鲜榨柠檬果皮和果肉原汁对7种常见食源性致病菌的抑菌效果以及对生物被膜形成的影响。方法对柠檬果皮和果肉分别榨汁测定总酸;采用顶空取样结合气相色谱-质谱联用技术(GC-MS)分析鲜榨柠檬果皮和果肉原汁中的主要挥发性成分;采用平板抑菌试验研究两种鲜榨原汁的抑菌效果;采用试管法和96孔板法研究两种鲜榨原汁对细菌生物被膜形成的影响。结果鲜榨柠檬果肉原汁总酸为98.86 g/kg,鲜榨柠檬果皮原汁总酸为6.05 g/kg;GC-MS结果表明鲜榨柠檬果皮和果肉原汁中主要挥发性成分以柠檬烯、γ-萜品烯、α-松油醇、柠檬醛等为主;鲜榨柠檬果肉原汁对7种常见食源性致病菌均具有明显抑菌效果,鲜榨柠檬果皮原汁均未出现明显抑菌作用;鲜榨柠檬果肉原汁对部分细菌被膜形成有抑制作用,鲜榨柠檬果皮原汁对部分细菌被膜形成有明显促进作用。结论鲜榨柠檬原汁对常见食源性致病菌生长及被膜形成影响的研究为食源性致病菌的防控提供了科学依据。     

套袋对柠檬香气成分的影响

为了研究套袋技术对柠檬香气的影响,以套袋安岳柠檬的果皮果肉为研究对象,未套袋柠檬为对照,采用顶空固相微萃取-气相色谱-质谱联用技术测定果皮和果肉香气成分,检出主要香气成分的相对含量从高到底依次为烯烃类、醇类、醛类、酯类和酮类等物质。结果表明:无论是否套袋,果皮始终比果肉的香气组分更加丰富,柠檬香气品质主要体现在果皮上;与对照相比,套袋后柠檬果皮果肉香气的主要组分仍保持基本一致;套袋后含氧萜类成分的相对含量减少,减少量均低于2.91%,套袋降低柠檬的香气品质,但降低程度不大。柠檬醛是柠檬中最重要的香气成分,两种同分异构体(橙花醛和香叶醛)的含量比很稳定,果皮中约2:3,果肉中约1:2。     

柠檬果皮香气成分的GC-MS分析

为研究柠檬果皮的香气特征和加强柠檬感官品质的调控,以同一生长环境的3个不同柠檬品种(粗柠檬、尤力克柠檬和北京柠檬)的果皮为研究对象,采用顶空固相微萃取技术联合运用气质联用技术进行果皮香气成分的分析测定,以内标法进行定量。分别检出尤力克柠檬、北京柠檬和粗柠檬各有67、65种和65种香气组分,主要有烯烃类、醇类、醛类、酯类和酮类物质。结果表明：柠檬感官品质的差异除了受环境的影响外,基因型的不同也起到决定性作用;尤力克柠檬比北京柠檬和粗柠檬具有更高的感官品质。     

白柠檬果皮油特征香气成分的评价

用客观方法 ,评价了白柠檬果皮油的特征香气成分。用溶剂萃取法提取白柠檬果皮的精油 ,并用硅胶柱将精油分成碳氢化合物和含氧化合物两大部分 ,由于含氧化合物部分具有果皮油的特征香气 ,利用各成分的香气值对该部分进行了评价 ,明确了香叶醛、橙花醛、沉香醇以及一些脂肪族醛等 2 5种成分对白柠檬果皮油香气起着重要作用。用这些成分按着在果皮油中的含量比调配成的混合液具有白柠檬果皮的香气。由此可知 ,利用香气成分的香气值 ,能够筛选出对食品的香气起重要作用的成分。     

4种柠檬不同组织的酚类物质分布及其抗氧化特性

采用分光光度计法评价4种柠檬(尤力克黄柠檬、小青柠、青柠檬、香水柠檬)中果皮与果肉的总酚含量与抗氧化活性(清除ABTS+自由基能力、铁离子还原能力和清除DPPH自由基能力),并用超高效液相色谱对其酚类物质进行定性和定量。结果表明:4种柠檬果皮中的总酚含量及抗氧化活性均显著高于果肉(P0.05),其中尤力克果皮与果肉的总酚、抗氧化活性均显著高于其余3个品种(P0.05),而香水柠檬果皮与果肉中总酚、清除ABTS+自由基能力均最低。不同品种柠檬中酚酸、类黄酮种类及含量差异较大。从4种柠檬中共检出21种酚类物质,其中酚酸6种,黄酮6种,黄烷酮6种,多甲氧基黄酮3种。柠檬中的酚类物质主要是黄烷酮,占类黄酮总量61.82%～91.61%,其中青柠檬果皮中酚酸总量最高(535.62 mg/100 g DW),尤力克果皮中类黄酮总量最高(1 506.33 mg/100 g DW),果肉规律与果皮基本一致,然而其含量显著低于果皮含量(P0.05)。从尤力克果皮与果肉中共检出15种酚类物质,其中圣草枸橼含量最高,而新绿原酸是含量最高的酚酸。从小青柠、青柠檬和香水柠檬的果皮与果肉中分别检测出19,16,15种酚类物质,其中橙皮苷含量均最高,而香草酸是含量最高的酚酸。不同品种柠檬的总酚和总类黄酮含量与ABTS+呈极显著的正相关性,同时总酚含量与DPPH呈显著性的正相关性。     

采后乙烯脱绿改善“尤力克”柠檬贮藏品质

为了评估贮藏时间对乙烯脱绿柠檬和套袋柠檬的理化特性和果皮中挥发性风味物质的影响。将乙烯脱绿后的柠檬与套袋柠檬于(9±1)℃的条件下贮藏13周,计算果实质量失重率、硬度以及果皮所占比例,用每种果实的果汁测定的总酸、抗坏血酸、可溶性固形物(total soluble solid, TSS),丙二醛含量,并测定果皮中挥发性风味物质。结果表明,乙烯脱绿柠檬总酸、抗坏血酸、TSS、失重率、丙二醛、挥发性风味物质在贮藏过程中均表现出较高水平,硬度则在贮藏初期表现为较低水平,在贮藏后期硬度大于对照组。采后乙烯脱绿处理可以在改善柠檬果皮颜色以及果实品质的基础上,保证其贮藏品质,满足柠檬成熟季节之外的市场需求。     

采后乙烯脱绿处理“尤力克”柠檬

为探究采后乙烯脱绿处理对尤力克柠檬果皮颜色以及果实品质的影响,采用质量浓度为5 mg/L的乙烯,在28℃条件下对柠檬脱绿5 d,分别分析了果皮与果肉主要品质指标的变化,对比了脱绿处理柠檬与套袋处理柠檬的品质。结果表明,采后乙烯脱绿处理的果实硬度显著小于对照组与套袋组(P <0. 05),果皮中a*值、类胡萝卜素、氨基酸、总酚、黄酮、丙二醛含量显著上升(P <0. 05),L*、b*值、蛋白质含量无显著变化,叶绿素含量下降了36. 37%,果肉中的总酸、Vc、TSS、蛋白质、氨基酸、总酚、丙二醛等无显著变化,黄酮含量上升了14. 28%。采后乙烯脱绿处理可以有效改善柠檬果皮颜色以及柠檬果实品质,为今后生产上的应用提供了理论参考。     

椪柑、温州蜜桔果皮中酚类物质组成及抗氧化能力研究

目的:研究椪柑、温州蜜桔果皮中酚酸与黄烷酮糖苷组成及其抗氧化能力。方法:高效液相法测定椪柑、温州蜜桔果皮中九种酚酸和两种黄烷酮糖苷的组成与含量。用福林酚法、ABTS法和FRAP法对椪柑、温州蜜桔果皮甲醇提取液抗氧化能力进行评价。结果:柑橘果皮中可溶酯化酚酸部分所占比例最大,肉桂酸型酚酸是柑橘皮中的主要酚酸,且主要以酯化形式存在,其含量排列顺序一般为:阿魏酸>对香豆酸>芥子酸>咖啡酸。温州蜜桔果皮中有较高总酚酸含量(p<0.05)。椪柑果皮主要含橙皮苷,温州蜜桔果皮含橙皮苷和少量柚皮芸香苷。温州蜜桔果皮中总黄烷酮糖苷含量高于椪柑(p<0.05)。总的来说椪柑果皮提取液抗氧化活性略高于温州蜜桔。结论:HPLC测定柑橘皮中酚酸与黄烷酮糖苷可取得良好结果,抗氧化实验表明柑橘皮具有一定的抗氧化能力。     

柑橘皮渣生物转化燃料乙醇的研究进展

利用柑橘皮渣生物转化燃料乙醇是一种生产乙醇的安全可再生的方法。以柑橘皮渣为原料,通过酶或酸进行水解成可发酵糖液,利用糖酵解途径发酵乙醇的微生物将其转化为乙醇,提取脱水到99.5%浓度即得到燃料乙醇。这旨在解决柑橘产业大量副产物皮渣造成的环境污染资源浪费,同时生产乙醇作为枯竭的石油能源替代品。柑橘皮渣转化乙醇中,D-柠檬烯严重抑制微生物发酵,但合理控制各种影响因素可达到较高的乙醇产量。文中对柑橘皮渣生物转化燃料乙醇的过程及影响因素等进行了综述。     

水蒸汽蒸馏法提取柑桔类果皮香精油的工艺研究

本文研究了利用水蒸汽蒸馏法从沙田柚皮、芦柑皮、柠檬皮中提取香精油的工艺.考察了各种因素对得油率的影响.结果表明:沙田柚皮、芦柑皮、柠檬皮的最佳提取时间是90 min;适当破碎果皮可以提高得油率,但破碎度过大反而使得油率降低;烘干的沙田柚皮、芦柑皮、柠檬皮的得油率分别比新鲜的提高了55.2 %、19.5 %、77.5 %,但香精油的质量比新鲜的差;添加助剂氯化钠、硫酸钠、碳酸钙能提高沙田柚皮和柠檬皮的得油率,但不能提高芦柑皮的得油率.     

DESTRUCTION OF POTATO PEEL TRYPSIN INHIBITOR BY PEELING AND EXTRUSION COOKING

Potato peels, a by-product of potato processing, can serve as a source of concentrated dietary fiber, but potato trypsin inhibitors (TI) in peels could reduce nutritional quality. Peels prepared by two methods (abrasion or steam) were extruded at 110C or 150C with feed moistures of either 30% or 35%. Prior to extrusion, abrasion and steam peels contained 45.57 and 8.06 TIU/g, respectively. Extrusion reduced TI activity by 75–85% in abrasion peels, but no reductions were observed for steam peels. TI may not pose a nutritional problem for steam peels with or without extrusion. Abrasion peels should be extruded, or processed by another thermal method, prior to use in foods.     

Recovery and evaluation of aroma development in apple peels

Aroma in Delicious apple peels was generated by conditioning peels at ambient temperature (19–23°c) for 24 h. The conditioned peels were processed, and the developed aroma was recovered in a pilot-scale apparatus. The recovered aroma was evaluated for intensity and quality against standard apple essences derived from whole apples and unconditioned or no-delay peels. The strength or ‘flavouring capacity’ of the concentrated aroma solution was estimated by threshold analysis and by a matching standard procedure at single-strength juice equivalence. The aroma recovered from conditioned peels was 2–7 times stronger than that from similar no-delay peels. Quality of the aroma solution from conditioned peels was statistically (P > 0.05), indistinguishable from standard aroma solutions prepared from whole apples or no-delay peels. Thus, the conditioned peels gave aroma solutions with 2–7 times more ‘flavouring capacity’ than no-delay peels, without significant sacrifice in quality.     

Orientierende Untersuchungen über die Verwendung von Sonnenblumenschalen zur Herstellung von Platten

Results of investigations show that boards with particulary decorative surface can be made from sunflower peels. Using UF- or PMDI-resins board with good bonding quality were produced. PF-resin was unsuitable for gluing sunflower peels. The fat content, due to its hydrophobic properties, may be one reason of extremly low strengths of PF-bonded peels. Important is, moreover, the high content water soluble extractives. Here are further investigations necessary. The bending strength of one-layer-boards of coarse structured peels could be improved by using wood flakes for the surface layer.     

Composition and Pasting Properties of Breadfruit (Artocarpus communis Forst) from South-West States of Nigeria

Breadfruit (BF) is an underutilised crop in Nigeria. Information on its composition and the behaviour of its flour during cooking are important requirements for enhancing the utilisation of BF. Flours of BF obtained from three towns in South-West Nigeria were analysed for their chemical and pasting properties. Starch, crude fibre, ash, fat, protein and pasting properties were evaluated. Starch was the predominant carbohydrate, representing about 60.4 to 65.8% in the pulp and 47.5 to 57.5% in the peel. Crude fibre values varied from 6.31 to 9.04%. There was no significant difference between the crude fibre contents of the pulp and peels. Ash content ranged from 2.77 to 4.78% with the peels having significantly higher values than the pulp. Fat content ranged from 0.43 to 0.65%. The pulps had significantly higher protein content than the peels. Peak viscosity varied significantly across locations with the peels having significantly lower viscosity than the pulps. The peels were significantly hot stable with breakdown viscosity values of 6.92 to 7.95 RVU compared to the pulps (72.33 to 210.77RVU). Final viscosity of the pulp was higher than that of the peels. Higher setback viscosity values were observed in the pulps than the peels and the former cooked in significantly shorter time (3.67 to 3.77 min) than the peels (8.93 to 8.99 min). The study revealed considerable differences in the composition of breadfruit grown in different locations in Nigeria.     

Comparison of Peroxynitrite-Scavenging Capacities of Several Citrus Fruit Peels

Citrus fruit peels contain a large variety of bioactive components and are considered as potential sources of functional components. The purpose of this study was to evaluate the peroxynitrite-scavenging activities of different citrus fruit peels. The peroxynitrite-scavenging activities of methanolic extracts of nine dried citrus fruit peels were evaluated as determined by their ability to attenuate the peroxynitrite-mediated nitrotyrosine formation in albumin. The results showed that all of the tested citrus fruit peels had the ability to attenuate the formation of nitrotyrosine. The total phenolics contents highly correlated with the peroxynitrite-scavenging activities. The results also indicated that the peroxynitrite-scavenging activity of citrus fruit peels was mainly attributed to the total phenolics.     

压榨对酿酒葡萄皮渣酚类物质提取及抗氧化活性的影响

酿酒葡萄皮渣（皮和籽）生物活性物质含量丰富,具有很高的再加工利用价值。对鲜葡萄皮渣进行压榨处理后再干燥,研究压榨对皮渣的酚类物质提取及抗氧化活性的影响。结果表明：压榨处理可以快速降低葡萄皮渣水分含量,缩短干燥时间、提高可溶性膳食纤维提取率。压榨葡萄皮总酚、原花青素的提取量均有所增加,其含量分别为19.56 mg/g和22.64 mg/g。压榨葡萄皮的抗氧化能力高于未压榨葡萄皮,其DPPH、ABTS及羟自由基清除率分别为62.90%、70.18%和41.09%,铁氰化钾还原能力及金属离子螯合能力分别为0.23%和21.33%。压榨籽和皮籽混合物的酚类物质和抗氧化活性则明显降低。抗氧化活性与总酚、原花青素存在显著的相关关系（P＜0.01）。     

Valuable components of raw and ripe peels from two Indian mango varieties

Mango is one of the most important tropical fruits and India ranks first in its world production. During the processing of mango, mainly for mango pulp and preparation of amchur powder, peel is a by-product. Peel forms about 20% of the whole fruit and at present it is a waste product and its disposal has become a great problem. With a view to exploit mango peel as a source of valuable components, in the present study, proximate composition, polyphenols, carotenoids, dietary fibre contents and activities of few enzymes in raw and ripe peels of two Indian mango varieties, namely, Raspuri and Badami were determined. The polyphenol contents in these peels ranged from 55 to 110 mg/g dry peel. Dietary fibre content ranged from 45% to 78% of peel and was found at a higher level in ripe peels. Similarly, carotenoid content was higher in ripe fruit peels. Vitamins C and E contents ranged from 188 to 392 and 205 to 509 μg/g dry peel, respectively; and these were found at a higher level in ripe peels. Both raw and ripe mango peels exhibited significant amount of protease, peroxidase, polyphenol oxidase, xylanase and amylase activities.