Nutritional quality of important food legumes

The proximate composition, mineral constituents and amino acid profile of four important legumes (chickpea, lentil, cowpea and green pea) were studied in order to evaluate their nutritional performance. Significant (P < 0.05) variations existed among the legumes with respect to their proximate composition, mineral constituent and amino acid profile. Lentil was found to be a good source of protein, while cowpea was good in ash among the grain legumes tested. All four types of legumes were also better suppliers of mineral matter, particularly potassium, phosphorus, calcium, copper, iron, and zinc. However, the concentrations of various mineral constituents was not in good nutritional balance. It was concluded that the four legumes tested were rich in lysine, leucine and arginine and can fulfil the essential amino acid requirement of human diet except for S-containing amino acids and tryptophan. In order to make good, the deficiency of certain essential amino acids in legume protein, they must be supplemented with other vegetables, meat and dairy products (e.g., Whey, yogurt).     

Nutritional quality of chestnut (Castanea sativa Mill.) cultivars from Portugal

Chemical composition of eight sweet chestnut cultivars from the three protected designation of origin (PDO) areas in the Trás-os-Montes region were studied: Aveleira, Rebordã, Trigueira and Zeive from PDO ‘Terra Fria’, Demanda, Longal and Martaínha from PDO ‘Soutos da Lapa’ and Judia from PDO ‘Padrela’. Chestnuts were characterised by high moisture content (∼50%), high levels of starch (43 g 100 g⁻¹ dry matter – d.m.) and low fat content (3 g 100 g⁻¹ d.m.). Nuts contained significant amounts of fibre (3% d.m.), were rich in K (∼750 mg 100 g⁻¹ d.m.), P (∼120 mg 100 g⁻¹ d.m.) and Mg (∼75 mg 100 g⁻¹ d.m.). Moreover, chestnuts are a good source of total amino acids (6–9 g 100 g⁻¹ d.m.). Amino acid profiles were dominated by l-aspartic acid, followed by l-glutamic acid, leucine, l-alanine and arginine. These results provide additional information about the nutritional value of each cultivar and confirm that chestnuts are an interesting healthy food.     

Nutrient composition of Australian retail pork cuts 2005/2006

A study of the nutrient composition of Australian pork was undertaken to determine whether new breeding, feeding and processing methods had resulted in any changes in pork samples in the market place since surveys undertaken in previous decades. Samples of 13 popular pork cuts were purchased from randomly selected supermarkets and butchers’ stores in urban areas across the socioeconomic scale in three States of Australia, and analysed, raw and cooked, separable fat and separable lean, for nutrient composition (proximate components, minerals, vitamins) in late 2005 and early 2006. Results showed that present-day pork separable lean tissue continues to be low in fat, in line with stated objectives of practices implemented by the industry in Australia. Pork remains a good source of protein and of thiamin and other water-soluble vitamins, the latter being detected at nutritionally significant levels in fat tissue as well as lean; folate was detected in most samples, lean and fat portions. Iron content appeared to be slightly lower than in previous decades.     

冬枣核油的营养成分和抗氧化能力分析

对冬枣核油的脂肪酸组成和营养成分进行分析,并测定了其中极性成分与非极性成分的抗氧化能力。结果表明:冬枣核油含有11种脂肪酸,不饱和脂肪酸含量为74. 79%,其中油酸与亚油酸的含量较均衡,分别为39. 34%和33. 74%;冬枣核油中含有14种不皂化物,其中含有在普通植物油中不常见的γ-谷甾醇,占总不皂化物的53. 11%;冬枣核油中共检出3种生育酚和2种生育三烯酚,其中γ-生育酚含量(106. 34 mg/kg)最高,其次为α-生育酚(31. 48 mg/kg);冬枣核油中非极性成分抗氧化能力高于极性成分,其清除DPPH自由基和ABTS自由基的能力分别为114. 95mgTE/kg和207. 8 mgTE/kg。     

五种枣成分及功能研究

对五种枣的主要成分、无机元素、维生素以及总酚含量进行分析研究,并探讨总酚含量与抗氧化的关系.五种枣中总糖含量为80.86%～85.63%,还原糖含量为57.61%～77.93%,纤维素含量为6.13%～8.90%,蛋白质为4.75%～6.86%,脂肪含量为0.37%～1.02%,金丝小枣非还原糖的含量较高,其蛋白质和灰分的含量较低,故适合作为提取枣多糖的原料.五种枣中钾、钙、镁的含量较高,铁、钠、锌、铜的含量较低,硒未检出.五种枣中总酚含量为5.18～8.53mg/g,其中牙枣和尖枣因总酚含量较高,故适合作为提取酚类化合物的原料;五种枣的总酚含量与总的抗氧化能力没有相关性.     

Proximate composition and amino acid and mineral contents of Mormordica charantia L. pericarp and seeds at different maturity stages

The three maturity stages found in the pericarp and seeds of bitter melon (Momordica charantia) were investigated for their variations in proximate composition, amino acid profiles, and mineral contents. Moisture, starch, and total dietary fibre contents of pericarp, from all maturity stages (immature, mature and ripe), were significantly higher (P value <0.05) than those of ripe and mature seeds, while lipid and protein contents of seeds were statistically higher (P value <0.05) than those of pericarp. Maturity did not change the lipid content of the pericarp, while maturity progression decreased the protein content of bitter melon pericarp. A significant increase in the protein (30.4%) and lipid (37.6%) contents was observed in bitter melon seeds as the maturity progressed. Ripe seeds that have more than 30% protein could be a good protein source for functional ingredients in a food system. Bitter melon can be considered a good source of these nutrients.     

不同枣品种果实中功能性成分含量的比较研究

采用紫外分光光度法对10个枣品种果实中总黄酮、总酚、三萜和皂苷等活性物质成分含量进行测定分析,评价不同枣品种果实功能性产品的开发价值。结果表明,10个枣品种果实中总黄酮、总酚、三萜和皂苷含量平均值分别为3.07、17.39、39.45、30.50 mg/g,相关性分析显示三萜含量与皂苷含量呈极显著的正相关。不同枣品种各活性物质成分含量对比和对应分析结果均显示,总黄酮与总酚含量最高的枣品种分别为灰枣优株、京39,三萜与皂苷含量最高的枣品种均为赞2与骏1。灰色关联度法研究表现为枣果实中功能性成分含量综合表现较高的枣品种依次为赞2、灰枣优株、京39、中枣1号、骏1,可作为新疆枣功能性产品开发的适宜品种。     

壳聚糖在红枣汁澄清中的应用

在采用壳聚糖澄清红枣汁中，研究了壳聚糖用量、温度、pH对澄清效果的影响。结果表明：壳聚糖澄清枣汁透光率可达98％以上，清汁与原汁相比，VC含量、可溶性固形物含量稍有下降。总糖含量变化不明显，其澄清优化工艺条件是壳聚糖用量3％(1％壳聚糖醋酸溶液)、温度45℃、pH3．5。     

The effect of cooking methods on mineral and vitamin contents of African catfish

Proximate composition, mineral and vitamin contents (A, E, B₁, B₂, niacin and B₆) were investigated in cooked African catfish. Different cooking treatments were used (baking, grilling, microwaving and frying). The protein and ash contents increased in all cooked fish. The fat content increased only in fried fillets. The moisture content of cooked fish decreased. Mineral levels were affected by cooking methods, except for Cu Although the vitamin A content significantly increased in grilled and fried fish, vitamin E increased in all cooked fish. Vitamin B₁ content of cooked fish significantly decreased. Vitamin B₂ and niacin contents of grilled fish increased significantly. B₆ content of cooked fish significantly decreased but this did not occur for the grilled fish. High levels of vitamin and mineral contents were found in grilled catfish.     

HPLC法同时测定枣叶中5种黄酮的含量

建立了一种枣叶中黄酮类成分定量分析的HPLC方法,并对14个品种的大枣及酸枣叶中这5种黄酮的含量进行了分析。结果得到采用Hypersil BDS C18色谱柱,以乙腈与0.1%甲酸水溶液为流动相梯度洗脱,流速1 m L/min,柱温30℃,检测波长360 nm,实现了槲皮素-3-O-洋槐糖苷、芦丁、槲皮素-3-O-β-D-葡萄糖苷、山奈酚-3-O-芸香糖苷、槲皮素-3-O-α-L-阿拉伯糖-（1→2）-α-L-鼠李糖苷5种黄酮苷的同时检测,最低检出限为1.44².59μg/m L,加标回收率在93.8%¹05.9%之间。5种黄酮苷的含量测定结果表明不同品种的枣叶中黄酮类成分的组成和含量差异较大,其中芦丁和槲皮素-3-O-洋槐糖苷的含量较高,平均为7.83 mg/g D.W和4.61 mg/g D.W;8个品种枣叶中检测到槲皮素-3-O-α-L-阿拉伯糖-（1→2）-α-L-鼠李糖苷,平均5.32 mg/g D.W;而槲皮素-3-O-β-D-葡萄糖苷和山奈酚-3-O-芸香糖苷的含量较低,分别为0.14 mg/g D.W和0.41 mg/g D.W。      

不同品种枣果果实品质分析与评价

试验研究6个品种枣果的理化品质特性,评价指标主要包括可溶固形物(TSS)、可滴定酸、糖酸比、还原糖、可溶性糖、有机酸和游离氨基酸。结果表明:葡萄糖、果糖和蔗糖是其主要可溶性糖,且均以蔗糖含量最高;苹果酸和琥珀酸是其主要有机酸,占有机酸总含量92%以上;脯氨酸是其含量最丰富的氨基酸,占总游离氨基酸68%以上,其次是天冬氨酸。梨枣因含水量高,酸度低、可食率高、糖酸比适中,适合鲜食;哈密大枣和木枣含糖量高、含水量低、酸度较高、糖酸比高,适合干制;金丝小枣与灰枣酸度较高,但TSS与糖含量也较高,可鲜食也可干制。     

Extending the shelf-life and proximate composition stability of ready to eat foods in vacuum or modified atmosphere packaging

The stability of the proximate composition (moisture, proteins, lipids and ash) and the microbiological state of cooked ‘ready to eat’ foods in vacuum or modified atmosphere packaging were examined and compared with conventionally packaged (in air) foods. The study was carried out for 7 and 29 days, during which time the food products were stored at 3°C. Vacuum or modified atmosphere packaging were effective for prolonging the shelf-life of the studied products up to 29 days with minimal changes in the proximate composition. Aerobic mesophilic, psychrotrophic microrganisms, and yeasts and moulds increased with time regardless of packaging type but more rapidly under conventional packaging.     

Chemical characterization and properties of five deep-sea fish species

Some important flesh properties were determined for the deep-sea species Portuguese dogfish (Centroscymnus coelolepis), leafscale gulper shark (Centrophorus squamosus), black dogfish (Centroscyllium fabricii), roughhead grenadier (Macrourus berglax), and mora/deepsea cod (Mora moro).Chemical composition, water holding capacity, cook loss and shelf-life, as indicated by bacterial counts, were determined. For some of the species investigated, variations could be observed between fish caught in spring and fish caught in summer. The fish used in this study were caught at Hatton Bank in the North Atlantic, where fishing takes place mainly from April to September.     

Nutritional composition and antioxidant activity in hazelnut shells from US‐grown cultivars

The hard shell of a hazelnut is a major waste of the hazelnut industry. The chemical composition, phenolic compounds (total phenolics, tannins and condensed tannins), antioxidant activity (DPPH and ABTS free‐radical scavenging assays), and the relationships between phenolic compounds and antioxidant activities of the hazelnut shells from twelve US grown cultivars were investigated to for potential commercial development. Crude fibre accounted for over 85% of total carbohydrate. The shells contained high concentrations of phenolic compounds. Concentrations of phenolic constituents and ABTS^?+ ‐scavenging capacities were significantly higher (P > 0.05) in the Oregon cultivars than their Nebraska counterparts. There were significant positive correlations between ABTS^?+ scavenging capacities and the phenolic compounds, whereas DPPH^? ‐scavenging capacity demonstrated a weak negative correlation with ABTS^?+ scavenging capacity and the phenolics. The results suggest that hazelnut hard shell may serve as a potential source of natural antioxidants for food applications.     

3种鲜枣贮藏期致病真菌的检测及定性研究

鲜枣采后贮藏期间易发生病害而腐烂。为深入研究危害采后鲜枣的主要病原菌和发病原因,以天津静海所产梨枣、圆铃枣、冬枣3个品种鲜枣为试材,对采后低温贮藏后期的病原菌进行了分离和鉴定,并对其生物学性质进行了初步研究。结果表明,侵染梨枣的病原菌主要有根霉和交链孢。侵染圆铃枣的病原菌是交链孢,但主要表现为生理性病害酒化。侵染冬枣的病原菌主要是交链孢和裸孢壳菌。     

中国不同产地红枣的组分分析与评价

该研究首先针对红枣的浸提工艺进行,实验中通过对料水比、总糖含量以及提取率等进行单因素考察,并在此基础之上进行正交试验,最终得到红枣浸提最佳工艺为浸提温度70℃,浸提料水比1∶8,浸提时间45min。此外,利用本试验得到的红枣浸提工艺对国内的六大(新疆、山西、山东、陕西、河南、河北)主要产枣地区的红枣进行了营养成分的分析对比,以总糖含量、蛋白质含量、总黄酮含量和VC含量作为分析指标,最终得到,河北沧州红枣的总糖含量以及蛋白质含量均为最高,总黄酮和VC含量略低于其他产区;陕西清涧红枣的总黄酮含量和VC含量均为最高,可以作为生产保健食品的原料;山东沾化红枣的总糖含量最低,新疆和田红枣的蛋白质含量最低仅为3136.56mg/L,而山西吕梁和河南郑州的红枣中各项指标相差不大。该研究以期为红枣资源的研究和开发提供有益的帮助,而且对优良红枣品种的选育、高品质红枣果品的生产开发利用提供理论依据。     

冬枣减压贮藏试验研究

在(0±1)癈,大气压力分别为101.325、81.06、50.663kPa和20.265kPa的贮藏条件下,研究了冬枣的生理生化变化,同时初步筛选出较适宜的压力范围。结果表明,减压贮藏显著降低了冬枣VC的损失,延缓了TSS含量的增加和果肉硬度的下降,有利于保持CAT活性,显著抑制了PPO活性,从而延缓了果实的成熟衰老。     

大枣浓缩汁贮藏过程中非酶褐变动力学研究

在4,26,37℃条件下对大枣浓缩汁进行7个月的贮藏,并分别用零级、一级动力学模型对产品中与非酶褐变相关的指标还原糖、抗坏血酸(Vc)、羟甲基糠醛(HMF)随贮藏时间的变化进行拟合分析。结果表明:还原糖含量的动态变化零级模型拟合度优于一级的,Vc含量的动态变化一级模型拟合度优于零级的。4,26,37℃贮藏条件下,大枣浓缩汁中的HMF和A420变化呈线性关系,同时颜色参数(A420、L*、Chroma值)是HMF的函数,具有相关性,可用一级动力学方程表示。26,37℃贮藏过程中大枣浓缩汁的颜色参数及还原糖、Vc含量变化显著(P0.05),明显高于4℃贮藏,低温有利于大枣浓缩汁的贮藏。     

Nutritional properties of commercially grown native Australian fruits: Lipophilic antioxidants and minerals

A high level of antioxidant activity of lipophilic fractions obtained from commercially grown native Australian fruits, as evaluated in the oxygen radical absorbance capacity assay for lipophilic antioxidants (ORAC-L), was identified for the first time. The level of contribution of lipophilic fractions varied from 5.8% (quandong) to 30.7% (riberry) of the total oxygen radical scavenging capacity (ORAC-T). Vitamin E components - ??-tocopherol, ??-tocopherol and ??-tocopherol and lutein - were identified as the main sources of this activity. Among the evaluated sources, Kakadu plum emerges as a fruit with unique nutritional qualities: it exhibited a superior ORAC-T value (430.0 ??M trolox eq/g fresh weight, TEq/g FW) with 26.7% contribution of the lipophilic fraction. The major compounds of Kakadu plum's lipophilic fraction were ??-tocopherol (1.022 ± 0.1 mg/100 g, FW), lutein (0.26 ± 0.01 mg/100 g FW) and chlorophyll a and b (2.72 ± 0.1 and 0.54 ± 0.1 mg/100 g FW, respectively). With regards to mineral content, the levels of major minerals, such as potassium, phosphorus, calcium, magnesium, and trace elements such as iron, zinc, manganese, selenium and copper as well as cobalt, nickel, aluminium and led in native Australian fruits are similar to the levels of these elements in a range of vegetables and frutis produced and consumed elsewhere.