Grain and malt quality properties of some improved Nigerian sorghum varieties

To determine their grain and malt quality properties, ten improved Nigerian sorghum varieties were subjected to several tests. The parameters that were tested included thousand corn weight, germinative energy, germinative capacity, water sensitivity, malting losses, hot and cold water extracts and free amino nitrogen (FAN). Results obtained showed variations among the sorghum varieties in most of the parameters assessed. While variety SK5912 was heaviest (40.25 g), variety Nafelen 6 had the lowest weight (22.45 g). For germinative capacity, variety KSV8 gave the highest value (97.0%), while variety ICSV400 gave the lowest value (90.5%). Variety KAT487 was the most water sensitive (5%), while four varieties simultaneously gave the lowest value. Boboje gave the lowest malting loss (13.77%), while the highest loss (37.74%) was given by White Kaura. For the extracts, variety SK5912 gave the highest value, as was the case also with FAN. Generally, there were significant differences across the different varieties of sorghum for malting loss, FAN, cold water extract and hot water extract at both p < 0.05 and p < 0.01. The results showed significant agreement with previous reports, with the key findings being that grain size mostly correlated positively with high expression of the critical malting parameters. Copyright © 2014 The Institute of Brewing & Distilling     

Effects of steeping and germination time on growth rate and phenolics content of Nigerian Sorghum bicolor and Sorghum vulgare seedlings

Moisture content and enthalpy, growth rates, and phenolics of germinating grains of Sorghum bicolor Moench (SK) and Sorghum vulgare L (LR) were evaluated as functions of steeping time, air-rest and formalin treatments, and germination time. Results obtained showed that 24-h steeping gave rise to the highest growth rate, which was greater for LR than SK. The moisture and enthalpy which gave rise to optimum germination rate were 0.48 and 0.48 kg kg^?1, 422.69 and 392.32 kJ kg^?1 for LR and SK, respectively. Air-rested steeping effected the maximum growth rate as well as high phenolics retention in the germinated grains. Formalin re-steeping imparted 71.32 and 68.88 % reduction in phenolics in LR and SK, respectively, while causing very low growth rate in the seedlings. However, no significant difference was found (P = 0.05) between FRS and low-temperature steeping for the two parameters.     

不同浸渍工艺对蛇龙珠干红葡萄酒香气成分的影响

以河西走廊产区蛇龙珠葡萄为原料,采用顶空固相微萃取（headspace solid-phase microextraction,HS-SPME）结合气相色谱-质谱联用仪（gas chromatography-mass spectrometry,GC-MS）分析检测自然浸渍、冷浸渍、EX酶浸渍、卡乐酶浸渍、CO₂浸渍、热浸渍40℃、热浸渍60℃七种浸渍工艺对葡萄酒理化指标及香气物质的影响。结果显示:自然浸渍干浸出物含量最高,CO₂浸渍总酸含量显著低于其他工艺,热浸渍60℃总酚、单宁、色度值最高,色调在各组间差异显著（p<0.05）。酒精发酵结束后共检出78种香气成分,对于酯类物质,热浸渍60℃含量最高,其次是热浸渍40℃、卡乐酶浸渍、CO₂浸渍,自然浸渍含量最少。与自然浸渍相比,其他各工艺醇类物质含量都有所提升。热浸渍60℃与CO₂浸渍萜烯类物质较高,CO₂浸渍后脂肪酸含量最低。热浸渍60℃果香和玫瑰花香最强,卡乐酶浸渍脂肪味最浓郁。综上,不同浸渍工艺所酿葡萄酒香气差异较大,且热浸渍60℃更加适宜于河西走廊蛇龙珠葡萄酒的酿造。      

Effect of teff (Eragrostis tef) variety and storage on malt quality attributes

Varieties of a cereal may have a considerable influence on malting qualities owing to variations in the physicochemical properties of the grains. This research was aimed at assessing the influence of five teff varieties on malt quality attributes. The teff samples were malted using previously optimized malting conditions and mashed with the congress mashing procedure. In this research, the Kuncho teff variety was malted in a one year period after harvesting, whereas the other four varieties were malted after three years of storage. Alpha‐ and β‐amylase, and limit dextrinase activity, were in the ranges 14–68, 10–440 and 375–1072 U/kg, respectively. Extracts ranged from 54% for Dessie to 74% for Ivory teff. Free amino nitrogen, protein content, soluble nitrogen, Kolbach index, viscosity and wort colour were in the ranges 160–364 mg/L, 8.6–13.6%, 532–1048 mg/100 g, 24–50%, 1.441–1.629 mPa s and 5.9–9.0 EBC units, respectively. High‐performance liquid chromatographic analysis for individual fermentable sugars revealed that the highest value in all varieties was recorded for glucose followed by maltose. The concentration of glucose ranged from 9.49 g/L in Brown teff, to 19.42 g/L in Ivory teff, whereas maltose ranged from 2.95 g/L in Dessie teff to 16.1 g/L in Kuncho teff. All of the malt quality attributes considered in this study were markedly influenced (p < 0.05) by the type of teff cultivar. It was concluded that the use of different teff varieties yielded malts with significantly different malt quality attributes. Copyright © 2013 The Institute of Brewing & Distilling     

Effect of consecutive steeping on antioxidant potential of green,oolong and black tea

After water, tea is considered to be one of the most consumed drinks worldwide. To get the maximum benefit from the whole‐leaf teas, the manufacturers provide instruction that these teas can be steeped 2–3 times over 6–8 h. In this study, the effect of consecutive steeping on radical‐scavenging ability of whole leaf green tea (unfermented), oolong tea (partially fermented) and black tea (fully fermented) was determined. Green tea showed the highest level of antioxidant activity, total phenolic and flavonoid content followed by oolong tea and black tea irrespective of the number of steeping done. The result also demonstrated that re‐steeping reduced the antioxidant potential of teas. Moreover, it was revealed that green tea is the best candidate for re‐steeping followed by oolong and then black tea.     

干燥温度对核桃品质的影响

为了探明不同温度干燥处理对核桃品质的影响,研究了核桃在温度40、50、60℃干燥条件下进行烘干处理,以日晒为对照,观察了在烘干过程中乌米核桃和威宁泡核桃的水分含量、酸值、过氧化值和水分活度等品质指标的变化。结果表明,核桃经干燥后水分及水分活度显著下降,酸值及过氧化值显著上升,核桃的酸值、过氧化值与干燥温度呈正相关,营养物质的含量随干燥温度的升高而不断升高。两种核桃经干燥处理25h后,相同干燥温度处理后的水分含量无显著性差异,40、50℃及日晒处理的过氧化值和酸值变化最小,产品的口感较好,但干燥时间长,特别是日晒,所需时间长,品质不能保证;60℃处理的水分活度最低,干燥15h时水分活度就已达安全水分活度,可防止大多数微生物存活,有效延长贮藏期,综合考虑干燥核桃的品质、贮藏期及生产成本,以60℃处理15h干燥核桃为佳。      

Effect of malt pretreatment on phytate and tannin level of two sorghum (Sorghum bicolor) cultivars

The seeds of two cultivars of Sudanese sorghum (Sorghum bicolor), namely Wad Ahmed and Tabat, were germinated for 4 days to obtain 1‐, 2‐ and 4‐day‐old malts. Sorghum malt (5% and 10%) was added to sorghum flour. The mixtures were incubated at 30 °C with shaking for 30, 60, 90 and 120 min. Malting loss was very slight for both cultivars and for all incubation periods. Phytic acid and tannin contents were assayed for all treatments. The results revealed that phytate and tannin contents were significantly (P ≤ 0.05) reduced when sorghum flour was pretreated with malt. When a mixture containing 10%, 4‐day‐old malt and sorghum flour was incubated for 120 min, it significantly (P ≤ 0.05) reduced phytate and tannin contents by 92% and 98%, respectively, for Wad Ahmed cultivar, while for Tabat they were reduced by 93% and 96%, respectively. The rate of reduction of phytate and tannin content increased with incubation time and malt age and concentration.     

焙焦温度对麦芽品质及酶活性影响

研究了不同焙焦温度对成品麦芽品质及酶活的影响.结果表明,随着焙焦温度的升高,麦芽的糖化力、α-AN、浸出物含量及水分含量都有所下降,且糖化力下降显著(α=0.041<0.05):色度、糖化时间、麦汁黏度随焙焦温度的升高而增加,淀粉酶活力都呈下降趋势,且β-淀粉酶活力下降极显著(α=0.0004<0.01);蛋白酶活力、β-葡聚糖酶活力、PPO活力都有所下降,且得出PPO的失活温度为82℃.     

食醋大曲培养温度对食醋品质的影响

在食醋的酿造过程中,大曲的生产至关重要,影响大曲的因素有原料配伍、拌料的水分、培养温度等。通过控制其他因素不变,研究了食醋大曲培养温度对食醋品质的影响。结果表明,培养温度控制在32 ℃时成曲中含的细菌最多,放线菌最少,霉菌数量和酵母菌相当。对不同温度条件下制成的大曲进行食醋酿造,以颜色、香气、味道、体态等作为组成主要影响因素,进行了产品的模糊综合评价。表明在32 ℃条件下培养而成的大曲用于生产,可以使食醋品质达到最佳。     

不同干燥条件对啤酒麦芽品质的影响

以甘啤4号大麦为原料,采用凋萎温度和焙焦温度相结合的方法,设置3个温度梯度,进行9组完全组合试验,对水分、浸出物、库值、α-氨基酸态氮、麦汁黏度和糖化时间等一系列指标的测定,得出了各个指标在干燥过程中的变化规律,并依据中华人民共和国行业标准(QB1686-93)啤酒麦芽综合评价评分表,对各样品进行综合评分,筛选出最佳的干燥工艺条件,确定了凋萎和焙焦的温度参数。     

温度对鲜切马铃薯生理和品质的影响

测定了鲜切马铃薯在2、12、25℃3个贮藏温度下生理指标和品质指标的变化。结果表明:与12℃和25℃相比,2℃贮藏条件显著抑制了鲜切马铃薯的失重率和呼吸强度,延缓其衰老进程;维持了较高的白度、硬度和可溶性固形物含量,保持了原有品质;有效地抑制了多酚氧化酶(PPO)和过氧化物酶(POD)的活性,从而减缓了鲜切马铃薯的褐变。为低温条件下鲜切马铃薯的贮藏提供了理论依据。     

冰温贮藏对采后葡萄果实品质的影响

为了明确冰温贮藏对葡萄果实品质的影响,对超冰温(-3,-2℃)、冰温(-1℃)及普通低温(4℃)4种不同贮藏温度下意大利葡萄的品质进行研究。结果表明:-3℃超冰温贮藏的意大利葡萄叶绿素、可滴定酸以及VC含量都相对较高,能较好地维持葡萄中营养成分不受损失,有利于葡萄在贮藏过程中保持较好的色泽及口感。     

不同温度条件下湘西苞谷酸发酵过程主要营养品质变化

湘西苞谷酸是一种以玉米和新鲜红辣椒为主要原料加工而成的风味独特的发酵食品,该研究对3种不同温度模式下苞谷酸发酵过程营养品质变化进行测定,并对3种温度条件下的产品进行感官评分。结果表明,3种温度模式下,随着发酵时间的延长,苞谷酸pH、淀粉逐渐降低,亚硝酸盐含量先增加后减少,总游离氨基酸含量呈现逐渐增加的趋势,发酵18 d后pH下降趋缓,游离氨基酸含量增加趋缓;25～30 ℃更利于湘西苞谷酸品质的形成,此温度条件下发酵36 d,苞谷酸pH3.8、淀粉含量33.3 g/100 g、蛋白质含量5.71 g/100 g、乳酸菌数对数值为5.03、亚硝酸盐3.8 g/kg、还原糖0.43 g/100 g、总游离氨基酸1.4 g/100 g。     

两段式冷却急冷温度对冷却猪肉品质的影响研究

研究了不同急冷温度(-14、-18、-22、-26、-30℃)对冷却猪肉品质的影响。结果表明,急冷温度的变化对冷却肉食用品质有显著影响(p<0.05),急冷温度为-22℃能显著提高冷却肉的保水性,改善色泽和质构,降低胶着性、咀嚼性和硬度,但对黏着性和弹性无显著影响;宰后45min胴体温度和pH对冷却肉保水性有预测作用,pH45min与冷却猪肉失水率呈负相关,宰后45min的胴体温度与失水率呈正相关。     

The effect of germination time on malt quality of six sorghum (Sorghum bicolor) varieties grown at Melkassa,Ethiopia

The effect of germination time (48, 96 and 144 h) on malt quality of six sorghum varieties was investigated to determine the potential of grain sorghum cultivars in the local brewery industry. Six sorghum varieties (Gambella 1107, Macia, Meko, Red‐Swazi, Teshale and 76 T1#23) were evaluated in a randomized complete block design with three replications. The results showed that both germination time and variety had a significant effect (p ≤ 0.05) on sorghum malt quality. The hectolitre weight (kg hL^?1 at 12.5% moisture), germination energy (%), crude protein (%) and flour starch amylose content (%) were: 75.8–82.9, 96–99, 7.0 ? 11.9 and 16.0 ? 23.0, respectively. The sorghum malt diastatic power (DP, °L), free amino nitrogen (FAN, mg L^?1), hot water extract (HWE, %) and malting loss (%) were: 18.96 ? 31.39, 185.67 ? 343.29, 41.85 ? 85.08 and 8.68 ? 27.56, respectively. Malting loss, HWE and FAN increased with germination time. The DP increased as the germination duration increased from 48 to 96 h, but the difference between 96 and 144 h was not significant. Considering the excessive malting loss and marginal increase in HWE beyond 96 h, this study suggests that the optimum malting duration would be around 96 h. Among the varieties tested, Teshale and Gambella 1107 produced the better malt quality. Copyright © 2012 The Institute of Brewing & Distilling     

Steeping‐induced physicochemical changes of milled waxy rice and their relation to the quality of yukwa (an oil‐puffed waxy rice snack)

The influence of water‐steeping periods (0 to 15 days, 25 °C) on the physicochemical properties of raw waxy rice in relation to the yukwa quality was investigated. The moisture contents in waxy rice and reducing sugar in its steeping medium were increased, while contents of protein and minerals of raw waxy rice were decreased in proportion to the water‐steeping duration. With longer steeping periods, swelling power, solubility and peak viscosity were increased, while grain hardness was decreased with apparent kernel structural change. Depending on the water‐steeping duration of raw waxy rice, the hardness decreased from 26.0 to 1.8 g, and the expansion ratio of yukwa increased from 762 to 1539%. Correlations between the physicochemical properties and yukwa quality indicated that variables having the most positive influential on expansion ratio were reducing sugar (γ = 0.961, P < 0.01) and peak viscosity (γ = 0.897, P < 0.01), and those for hardness of yukwa were crude protein (γ = 0.875, P < 0.01) and hardness (γ = 0.887, P < 0.01) of the steeped waxy rice. It is suggested that steeping‐induced physicochemical changes of raw waxy rice had a significant influence on the final quality of yukwa in terms of hardness and expansion ratio. Copyright © 2004 Society of Chemical Industry     

贮藏温度对全脂羊奶粉品质稳定性的影响

本文主要研究了贮藏温度(5、25和35℃)对全脂羊奶粉品质稳定性的影响。通过测定全脂羊奶粉的酸值(AV)、过氧化值(POV值)、硫代巴比妥酸值(TBA值)、溶解度、色值等指标反应贮藏期间品质的变化。结果表明,贮藏在35℃的全脂羊奶粉贮藏期间酸值、过氧化值、TBA值变化速率较快,分别于第4个月后、第2个月后、第3个月后显著高于贮藏在5℃和25℃的全脂羊奶粉(p<0.05);所有样品的溶解度和色值变化规律相似,但差异不显著(p>0.05)。因此降低贮藏温度可提高全脂羊奶粉品质稳定性。      

贮藏温度及护色剂对鲜切水芹贮藏品质的影响

为延长鲜切水芹的贮藏期,提高其贮藏品质,本文采用植物生理指标的常规检测方法研究了鲜切水芹在（5±1）、（15±1）、（25±1）℃贮藏条件下及在最适贮藏温度下经CA（柠檬酸）、PA（植酸）和L-Cys（L-半胱氨酸）等护色剂处理后的呼吸速率、失重率、叶绿素、抗坏血酸、还原糖和褐变度的变化规律。结果表明:在8 d的储藏期内,低温（5±1）℃较（15±1）℃更有利于降低水芹呼吸速率、褐变度和失水率,保持较高的还原糖、抗坏血酸和叶绿素含量;护色剂处理有抑制鲜切水芹褐变和衰老的作用,其中以0.25%L-Cys（L-半胱氨酸）效果为最好。      

老年人保健饮料：混合发酵海带饮料的工艺研究

介绍以海带为主要原料,经乳酸菌发酵后,用科学方法调配制成特别适合老年人饮用的保健饮料的工艺过程,解决了海带饮料口味一直难以改善的问题