14 种侧耳属食用菌干品挥发性香味成分分析

挥发性香味成分是影响食用菌品质的重要指标。为探究不同侧耳属食用菌挥发性香味物质的组成和相对含量,采用顶空固相微萃取结合气相色谱-质谱联用方法对14 种侧耳属食用菌干品中的挥发性香味物质进行分析,并通过相对气味活度值（relative odor activity value,ROAV）和共有成分分析研究不同组分对整体风味的贡献。结果显示：14?种侧耳属食用菌干品中共鉴定出41?种挥发性化合物,主要包括醛类、醇类、酮类、酯类、羧酸类和呋喃类等;其中共有成分8?种,分别为正己醛、2-丁基-2-辛烯醛、1-己醇、1-辛烯-3-醇、正辛醇、2-辛烯-1-醇、3-辛酮和1-辛烯-3-酮;此外,醇类化合物在14?种侧耳属食用菌中相对含量远高于其他类化合物。除佛罗里达侧耳PF6中主体挥发性香气成分为1-辛烯-3-酮、1-辛烯-3-醇和正辛醛外,其他13?种侧耳属食用菌中主体挥发性香气成分均为1-辛烯-3-酮和1-辛烯-3-醇。共有香气物质主成分分析显示前3?个主成分方差累计贡献率达到83.627%,主要代表性成分为1-己醇、正己醛、2-丁基-2-辛烯醛、正辛醇、2-辛烯-1-醇、1-辛烯-3-酮和3-辛酮等,它们是影响食用菌风味的关键性香味成分。     

不同工艺核桃油挥发性物质比对及关键香气成分表征

以有机溶剂浸提法和压榨法（冷榨和不同烘烤处理的热榨）制备的核桃油为研究对象，通过顶空-气相色谱-质谱联用仪测定其挥发性物质构成，结合相对气味活度值（relative odor activity value，ROAV）、主成分分析（principal component analysis，PCA）和聚类热图的计算分析明确核桃油中的关键香气成分构成差异，以期为核桃油风味品质控制提供理论依据。结果表明不同工艺核桃油样品的挥发性物质构成存在显著差异性（P＜0.05），11?个核桃油样品中共鉴定出92?种挥发性物质，主要包括醛类、烃类、醇类和含氧杂环类，其中压榨核桃油中反-2-庚烯醛（21.00%～28.61%）、正己醛（15.09%～20.72%）和顺-2-辛烯（9.77%～16.28%）相对含量较高，而有机溶剂浸提核桃油中正己醛（35.79%）、反-2-庚烯醛（13.46%）和戊醛（11.79%）相对含量较高。结合ROAV计算和PCA确定壬醛（油脂、柑橘和青草味）、反-2-壬醛（黄瓜、油脂、青草味）、反,反-2,4-癸二烯醛（油炸、蜡、油脂味）和1-辛烯-3-醇（蘑菇味）是核桃油中的关键香气成分。通过挥发性物质聚类热图分析发现不同工艺核桃油样品之间色差较大，表明基于挥发性物质进行不同工艺制备核桃油的区分判别具有可行性。     

乡城和楚雄牛肝菌营养风味品质对比分析

为比较四川乡城和云南楚雄两个产地的牛肝菌菌帽、菌柄的营养成分及挥发性成分的差异,测定其水分、蛋白质、粗脂肪、多糖、氨基酸含量,以及采用固相微萃取结合气相色谱质谱联用法测定其挥发性物质。结果表明：不同产地牛肝菌在营养成分含量上存在明显差异,其中楚雄牛肝菌帽蛋白质含量最高[（33.52±0.76）%],乡城牛肝菌柄粗脂肪含量最高[（5.46±0.13）%],楚雄牛肝菌帽多糖含量最高[（19.22±0.09）%]。乡城牛肝菌柄的氨基酸总量最高,而乡城牛肝菌帽氨基酸评分高于其他3 种牛肝菌。共鉴定出45 种挥发性风味物质,包括5 种烃、22 种醛、7 种醇、8 种酮以及3 种含氮含硫及杂环。利用相对气味活度值（relative odor activity value,ROAV）对牛肝菌主体挥发性香味成分分析得出,乡城牛肝菌的关键挥发性风味物质有两种,分别为1-辛烯-3-酮和1-辛烯-3-醇,楚雄牛肝菌的关键挥发性风味物质只有1-辛烯-3-酮。楚雄和乡城牛肝菌的风味物质的组成和含量有较大差异,营养成分的含量也不同,其中乡城牛肝菌柄的营养风味品质综合更佳。     

HS/SPME-GC/MS法比较分析野生与人工栽培羊肚菌挥发性成分

采用HS/SPME-GC/MS对野生与人工栽培羊肚菌的挥发性成分进行提取及检测分析,并采用相对气味活度值(ROAV)判定关键风味物质。在野生和人工栽培羊肚菌菌盖干品中,共检测出42种挥发性成分,野生羊肚菌中共检出24种挥发性成分,主要是5种醛类、8种醇类、4种酯类化合物,相对含量最高的是正己醛(17.99%);人工栽培羊肚菌中检出29种挥发性成分,主要是8种醇类、7种醛类化合物,相对含量最高的是甲酸己酯(7.86%)。野生和人工栽培羊肚菌的共有挥发性成分有:3-甲基丁醛、戊醇、正己醛、3-甲基丁酸、甲酸己酯、庚醛、γ-戊内酯、1-辛烯-3-醇、正庚酸、反-2-辛烯醛。采用ROAV法进行风味评价,野生羊肚菌的关键风味物质包括3-甲基丁醛、正己醛、庚醛、1-辛烯-3-醇、正庚酸、反-2-辛烯醛、壬醛共7种;人工栽培羊肚菌的关键风味物质包括3-甲基丁醛、2-甲基丁醛、正己醛、1-辛烯-3-醇共4种。     

不同产地虾酱风味特征及差异分析

采用顶空固相微萃取-气质联用技术对不同产地虾酱的挥发性物质进行分析和鉴定,结合主成分分析法对其挥发性物质组成差异进行分析。结果表明,从4个产地虾酱中共检测到89种挥发性物质,包括醛、醇、酮、酸、酯、吡嗪、含硫类和烃类化合物等。通过主成分分析可得到不同产地虾酱特有的风味物质组成,其中广东广州产的虾酱特征风味物质为乙酸,3-乙基-2,5-二甲基吡嗪,2-甲基-5-异丙基吡嗪,2-乙酰-5-甲基噻吩,3-甲氧基苯硫酚等;安徽芜湖产的虾酱特征风味物质为β-紫罗兰酮,1-辛烯-3-醇,吲哚,2-乙基吡啶,2-庚酮,(E)-2-已烯醛等;山东威海产的虾酱特征风味物质为4-萜烯醇,2,4,6-三甲基吡啶,芳樟醇,2-乙基己醇,二甲基二硫,2,4-二甲基噻吩,2,5-二甲基噻吩等。不同产地虾酱中挥发性物质组成的差异使其形成了各自的风味特征,可为虾酱产地鉴别、品质评价和控制提供一定的科学依据。     

椴木木耳和袋栽木耳挥发性成分及特征风味物质比较分析

本文采用顶空固相微萃取分别提取椴木木耳、袋栽木耳的挥发性成分,采用GC-MS分析样品的挥发性成分组成,采用相对气味活度值(ROAV)判定特征风味物质,并对椴木、袋栽木耳的特征风味物质进行了比较。结果表明,从椴木木耳中检出45种挥发性成分,主要是醇类、酸类、醛类化合物,相对含量最高的是乙酸,占比14.57%。从袋栽木耳中检出46种挥发性成分,主要是醇类、酸类、醛类化合物,相对含量最高的是正十四烷,占比8.63%。采用ROAV法进行评价,椴木木耳的关键风味物质包括1-辛烯-3-醇、正己醛、壬醛、正庚醛、正戊醛、1-庚醇、正己醇,共7种。袋栽木耳的特征风味物质包括1-辛烯-3-醇、正己醛、正庚酸、1-壬醇、正戊醛、1-辛醇,共6种。     

基于相对气味活度值法的新疆大盘鸡中主要挥发性风味物质分析

采用固相微萃取和气相色谱-质谱联用技术对新疆大盘鸡中的挥发性风味物质进行萃取和分离鉴定,采用相对气味活度值法确定对新疆大盘鸡香气具有主要贡献作用和修饰作用的香气物质。结果表明：共检测出64 种挥发性风味物质,醇类和醛类物质含量所占比例较高,分别为26.9%、36.4%;柠檬醛、1-辛烯-3-醇、壬醛、己醛、β-紫罗兰酮、桉树醇、苯甲醛、D-柠檬烯、芳樟醇、β-月桂烯、辛醛、1-庚醇、庚醛及2-戊基呋喃14 种物质对新疆大盘鸡香气贡献较大;苯乙醇、苯乙醛、正己酸乙烯酯、苯甲醇、(E)-2-辛烯醛、戊醛、乙酸芳樟酯、α-蒎烯、茴香烯、β-罗勒烯、二烯丙基二硫、6-甲基-5-庚烯-2-酮、乙酸庚酯、正辛醇、3-辛酮、正己醇、1-壬醇、松油醇及苯乙烯对新疆大盘鸡的香气起修饰作用。     

基于气相色谱-离子迁移谱的市售酸奶挥发性风味物质差异分析

采用风味感官评价结合气相色谱-离子迁移谱技术,对庄园牧场3种口味的酸奶(炭烧、原味和黄桃燕麦)和4种不同品牌的黄桃燕麦酸奶(庄园牧场、伊利畅轻、蒙牛冠益乳和伊利安慕希)的挥发性风味物质进行了差异性分析,共鉴定了其中的44种挥发性组分。指纹图谱分析结果表明,3种庄园牧场酸奶的特征挥发性风味化合物分别为：正己醇、2-乙基-5-甲基吡嗪、庚醛、乙酸丙酯、苯甲酸乙酯和丁酸甲酯等;2-戊酮、2-庚酮、异戊醛、乙酸丁酯、1-戊醇、乙酸戊酯、糠醛和2-壬酮等;正己醛、乙醇、苯甲醛、乙酸乙酯、丁酸丁酯、芳樟醇、正己酸乙酯和氧化芳樟醇等。4个品牌黄桃燕麦酸奶的特征挥发性风味化合物分别为：乙醇、3-羟基-2-丁酮、丁酸甲酯、正己酸乙酯、苯甲酸乙酯、正己醛、己酸和丁酸丁酯等;2-甲基丁酸乙酯、庚醛、异戊醛、叶醇和芳樟醇等;正己醇、氧化芳樟醇、苯乙酮和乙酸丁酯等;2-甲基丁酸己酯、2-庚酮和2-壬酮等。各酸奶样品的特征挥发性风味化合物分析结果与风味感官评价结果相吻合。主成分分析结果很好地实现了不同酸奶样品间的区分。该研究建立了基于气相色谱-离子迁移谱分析酸奶挥发性风味物质的新方法,同时可为酸奶的风味改善和品质...     

螺蛳挥发性风味成分的分析与研究

以新鲜螺蛳为研究对象,采用顶空固相微萃取和气相色谱-质谱联用技术(HS-SPME-GCMS),对螺蛳挥发性风味成分进行萃取和鉴定,并运用相对气味活度法(ROVA)评价挥发性风味成分对总体风味的影响。结果显示:从新鲜螺蛳中共鉴定出40挥发性风味成分,包括醛类、酮类、醇类、硫醚类、呋喃类、吡嗪类、噻唑类等。其中,螺蛳的关键风味成分物质有以下6种(ROAV≥1):二甲基三硫醚、1-辛烯-3-醇、异戊醛、反-2-壬烯醛、己醛、苯甲醛。另外,庚醛、2,3-丁二酮、反-2-辛烯醛、正庚醇、2-戊基呋喃、3-辛酮、正戊醛、柠檬烯、二甲基二硫醚对总体风味也具有重要贡献(0.1=ROAV1)。     

不同菌种发酵所得酸豆乳风味物质的主成分分析

目的针对酸豆乳存在的重要感官缺陷,判断不同菌种发酵风味间的差异性。方法收集与酸豆乳风味相关的、具有代表性、实验设计合理、数据信息完整的文献,共提取了27种发酵菌种制得的酸豆乳风味物质测定数据,将其进行统计并标准化处理,根据各风味物质出现频率筛选出酸豆乳风味体系中主要的风味物质,结合阈值和含量计算香气活度值(odoractivityvalue,OAV)和相对气味活度值(relative odor activity value,ROAV)值,确定对酸豆乳风味起主要贡献的物质。将其作为研究对象,对不同菌种发酵豆乳的风味进行PCA主成分分析。结果对酸豆乳风味起主要贡献的物质有2,3-丁二酮、2,3-戊二酮、1-辛烯-3-酮、3-羟基-2-丁酮、乙醛、正己醛、2-辛烯醛、2,4-癸二烯醛、戊醛、己醇、1-庚醇、1-辛烯-3-醇、2-戊基呋喃。结论 27种菌种在4类风味物质(强豆腥味物质、奶香味物质、非豆腥味物质、弱豆腥味物质)的相对含量上存在显著性差异。     

玉米深加工综合利用的前景

本文重点介绍用玉米作原料的淀粉行业、发酵酒精行业利用其生产中的副产品———玉米胚芽提取高质量保健食用油     

甜玉米及其加工品营养特点与食用品质评价研究进展

近年来,我国甜玉米栽培面积和产量均大幅提高;但甜玉米加工技术及产品品质评价工作则相对滞后。该文对国内外甜玉米及其加工产品营养和食用品质研究进展进行综述,并针对我国目前加工产品形式单一、研究基础薄弱等状况提出展望。     

Performance of dairy cows fed annual ryegrass silage and corn silage with steam-flaked or ground corn

Twenty-four lactating Holstein cows were used in a 6-wk randomized block design trial with a 2 × 2 factorial arrangement of treatments to determine the effects of feeding ground corn (GC) or steam-flaked corn (SFC) in diets based on either annual ryegrass silage (RS) or a 50:50 blend of annual ryegrass and corn silages (BLEND). Experimental diets contained 49.6% forage and were fed as a total mixed ration once daily for 4 wk after a 2-wk preliminary period. No interactions were observed among treatments. Cows fed BLEND consumed more dry matter (DM), organic matter (OM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) than those fed RS, but total-tract digestibility of OM, NDF, and ADF was greater for RS than for BLEND. No differences in nutrient intake were observed among treatments during wk 4 when nutrient digestibility was measured, but digestibility of DM and OM was greater for SFC than for GC. Cows fed BLEND tended to produce more energy-corrected milk than those fed RS, resulting in improved efficiency (kg of milk per kg of DM intake). When diets were supplemented with SFC, cows consumed less DM and produced more milk that tended to have lower milk fat percentage. Yield of milk protein and efficiency was greatest with SFC compared with GC. Blood glucose and milk urea nitrogen concentrations were similar among treatments, but blood urea nitrogen was greater for cows fed GC compared with those fed SFC. Results of this trial indicate that feeding a blend of annual ryegrass and corn silage is more desirable than feeding diets based on RS as the sole forage. Supplementing diets with SFC improved performance and efficiency compared with GC across forage sources.     

Performance of lactating dairy cows fed ryegrass silage and corn silage with ground corn, steam-flaked corn, or hominy feed

Forty-eight mid-lactation Holstein cows were used in a 6-wk completely randomized block design trial with a 4 × 3 factorial arrangement of treatments to determine the effects of feeding different proportions of corn silage and ryegrass silage with supplemental ground corn (GC), steam-flaked corn (SFC), and hominy feed (HF) on the performance of lactating dairy cows. Forage provided 49% of the dietary dry matter in the experimental diets, which were formulated to meet National Research Council requirements. Ryegrass silage provided 100, 75, 50, or 25% of the total forage dry matter, with corn silage supplying the remainder. There were no interactions between the proportion of forage provided by ryegrass silage and energy supplement. Dry matter intake and milk protein percentage decreased linearly with increasing proportions of ryegrass silage, but milk protein yield was similar among forage treatments. There were no differences among forage treatments in milk yield, milk fat percentage and yield, and energy-corrected milk yield. Dry matter intake was higher and there was a tendency for increased milk fat percentage for GC compared with SFC or HF. No other differences were observed in milk yield or composition among energy supplements. Plasma urea nitrogen and glucose concentrations were similar among treatments. Under the conditions of this trial, our results indicate that feeding a combination of corn silage and ryegrass silage is more desirable than feeding ryegrass silage alone, whereas supplementation with GC, SFC, or HF supports similar levels of milk production.     

Effect of feeding a corn hybrid selected for leafiness as silage or grain to lactating dairy cattle

A leafy corn hybrid was compared to a grain corn hybrid as silage and high moisture grain to evaluate dry matter intake, milk yield, and milk composition. Sixteen multiparous Holstein cows averaging 97 DIM were used in a feeding trial based on 4 x 4 Latin squares with 21-d periods. Each of four diets contained (dry basis) 8% chopped hay, 42% corn silage, 11% high moisture corn grain, 10% whole, fuzzy cottonseed, and 29% protein concentrate. One diet used leafy corn as both high moisture grain and silage. A second diet contained grain corn hybrid (control) as both high moisture grain and silage. A third diet contained leafy corn for high moisture grain and control corn for silage and the fourth diet used control corn for high moisture grain and leafy corn for silage. Cows fed diets containing leafy silage produced more milk and milk protein and ate more DM than cows fed control silage. The corn hybrid used for high moisture grain did not influence milk yield or composition. Dry matter intake was greater for cows fed the diet containing both leafy high moisture grain and leafy silage than for cows fed both control high moisture grain and control silage, but milk yield and composition were not different. When fed as silage, the leafy corn hybrid used in this experiment supported greater DMI as well as higher milk and protein yields when compared to the grain corn hybrid.     

Lactation performance of dairy cows fed rehydrated and ensiled corn grain differing in particle size and proportion in the diet

Rehydrated and ensiled mature ground corn has high ruminal starch digestibility, but particle size (PS) and dietary starch proportion (ST) can affect starch digestion and lactating cow performance. We evaluated the effect of rehydrated and ensiled corn (REC), PS, and ST on intake, lactation performance, nutrient digestibility, ruminal fermentation profile, and chewing behavior of dairy cows. Kernels from an 84% vitreousness hybrid were finely (FN) or coarsely (CS) ground, yielding geometric mean particle sizes of 1,591 and 2,185 µm, respectively. Ground kernels were rehydrated [60% dry matter (DM)] and ensiled in 200-L buckets for ≥205 d. The grinding rate (t/h) was 3.9 for FN and 11.7 for CS. The PS did not affect DM loss (11.3% of ensiled) or silage pH (3.8). Samples of each bucket (n = 15/PS) before and after silage fermentation were incubated in situ for 0, 3, 6, 18, and 48 h in 4 rumen-cannulated lactating cows. Ensiling increased the effective ruminal in situ DM degradation (63.7 vs. 34.1%), regardless of PS. Sixteen Holstein cows (152 ± 96 d in milk) in 4 × 4 Latin squares (21-d periods) were individually fed a 2 × 2 factorial combination of low (LO) or high (HI) starch diets with FN or CS. Cows were fed the same REC incubated in situ. Varied concentration of starch in the diet (29.2 vs. 23.5% of DM) was achieved by partial replacement of REC (22.0 vs. 14.2% of DM) with citrus pulp (0 vs. 8.2% of DM). Milk, protein, fat, and lactose yields did not differ. Milk fat percentage was reduced and protein percentage was increased by HI. Treatment FN increased feed efficiency (energy-corrected milk/digestible organic matter intake) when fed with HI. Total-tract starch digestibility tended to be reduced by CS (96.4 vs. 97.2% of starch intake). Serum β-hydroxybutyrate was increased by LO. High-starch diet reduced the molar proportions of acetate and butyrate in ruminal fluid and increased propionate and isoacids. Particle size did not affect ruminal fermentation profile. Coarse grinding reduced plasma d-lactate concentration with HI. Diet HI reduced the proportion of daily intake from 1900 to 0700 h and induced preferential intake of feed particles <8 mm and greater refusal of particles >19 mm in the morning. Fine REC reduced rumination time per day and increased eating time per DM intake. Milk and plasma urea-N did not differ. Ensiling of mature flint corn for >200 d largely eliminated the effect of the PS of REC on the studied outcomes. The proportion of REC in the diet affected ruminal fermentation profile and milk solids concentration, but did not affect short-term performance and digestibility. Coarse grinding of REC may allow increasing the grinding rate and thus save labor and energy during ensiling.     

玉米蛋白开发利用新进展

该文介绍近年来玉米蛋白研究新进展,包括结构及其氨基酸组成,玉米蛋白改性,及玉米蛋白在食品中应用。     

玉米联产品工艺浅探

玉米联产品有:精制玉米粉、精制玉米糁、玉米油、玉米快餐粉等。本文介绍了玉米联产品加工工艺,包括玉米清理、破糁脱胚、压胚制粉、综合加工等部分的工艺流程、主要设备。     

甜玉米啤生产工艺的研究

本实验以甜玉米为研究对象,通过对玉米糊化、液化、糖化、发酵等工艺参数的研究和探讨,得出结果:玉米在含0.2%乳酸的热水中浸泡4h,100℃下糊化60min,在85～95℃下加0.3%酶液化,然后降温到60℃,加酶0.5%,糖化4h,最后在15℃下接种啤酒酵母发酵48h,得到色泽淡黄、晶莹透明、有典型玉米香气的发酵产品。     

即食玉米货架期间品质研究

跟踪监测即食玉米一年货架期内微生物指标、感观指标和营养指标变化,结果表明,即食玉米在一年货架期间内安全可食,具有较高营养价值.试验利用水煮和微波两种加热方式消除即食玉米回生现象;结果表明,热水加热3～5 min或微波加热2～3min,均可消除回生现象,保持玉米原有风味.