A chemical study of Tamarindus indica (Tsamiya) fruits grown in Nigeria

The edible part (pulp) of Tamarindus indica L fruit is relatively poor in protein (87.9 g kg^?1) and oil (25.3 g kg^?1) but the seed is a good source of both (269.3 g kg^?1 protein and 109.1 g kg^?1 lipid). Both the pulp and seed are good sources of calcium, and the seed of phosphorus, magnesium and potassium. Low levels of phytic acid and heat-labile trypsin inhibitors are present.     

Antioxidant activity of lettuce tree (Pisonia morindifolia R.Br.) and tamarind tree (Tamarindus indica L.) and their efficacy in peanut oil stability

Different solvent extracts of lettuce tree (Pisonia morindifolia R. Br.) and tamarind tree (Tamarindus indica L.) were tested for antioxidant activities. The extracts exhibited effective reducing power and higher radical scavenging efficacy against DPPH and hydroxyl radicals. They also showed metal chelating ability and inhibited peroxidation in the β-carotene/linoleic acid emulsion system. The extracts contained considerable levels of vitamin C, vitamin E, total phenolics, tannins, and total flavonoids estimated through standard spectrophotometric methods. As the acetone and methanol extracts of lettuce and tamarind tree recorded pronounced activities, their protective effects in stabilizing peanut oil were tested in terms of their peroxide value, free fatty acid contents, and p-anisidine values in comparison with the synthetic antioxidants butylated hydroxyanisole and butylated hydroxytoluene. Additionally, the antioxidant activity of the extract-treated oil samples and their phenolic contents were monitored to obtain a complete perspective of the influence of the phenolic compounds in oil stability. Results indicated that the selected leafy vegetables, besides acting as good sources of antioxidants, may serve as substitute for synthetic antioxidants in the stabilization of peanut oil.     

罗望子胶与常用胶体的复配研究

为探究K⁺对罗望子胶/κ-卡拉胶复合凝胶的特性及机理的影响,本文采用流变学、质构分析、微观结构和红外光谱四种方法,对不同K⁺添加量的复合凝胶的性能和结构进行研究。流变学结果显示,K⁺的添加使凝胶体系的模量升高,柔量和总形变量降低,K⁺添加量增至15 mmol/L时,表观粘度达到最高值2690 Pa·s;质构分析结果显示随K⁺添加量的增大,凝胶体系强度和硬度增大,但弹性和内聚性相对减少;而红外光谱和微观结构证明了K⁺可以促进两种凝胶体系之间的相互作用,使凝胶孔隙趋于致密均匀,在K⁺添加量15 mmol/L时孔径间壁最为规则结实。结果表明,K⁺的添加能够使凝胶体系表现较好的粘弹性和抗变形性,使网状结构更加紧密,为罗望子胶和κ-卡拉胶的复配应用提供了理论参考。     

新疆胡萝卜籽挥发油的气相色谱-质谱法分析

研究采用水蒸气蒸馏法对新疆胡萝卜籽中的挥发油进行了提取,并用气相色谱质谱技术对胡萝卜籽中的挥发油进行了分离和鉴定,确认出25种成分,占挥发油总含量的96.97％.采用面积归一化法确定各成分的相对百分含量,其主要成分为醇类化合物,占其总量的53.03％;其次为烯萜类化合物,占挥发油总量的43.40％;酸类化合物(0.14％);酮类化合物(0.06％);醚类化合物(1.44％).研究为新疆胡萝卜籽资源的开发利用提供了数据基础.     

长白山红松籽油的提取及脂肪酸成分分析

以长白山红松籽为原料,采用机械液压冷榨法萃取红松籽油,考察了上限压力、榨油温度、压榨周期、停歇周期对萃取效果的影响,确定了液压冷榨法萃取红松籽油的最佳条件:上限压力为15MPa,温度为45℃,榨油周期为4min,停息周期为9min,在此条件下,红松籽油出油率为60.3%。对冷榨法萃取的红松籽油进行了脂肪酸成分分析,共测定出8种脂肪酸:棕榈酸、亚油酸、油酸、硬脂酸、二十碳三烯酸、二十碳二烯酸、二十碳烯酸、二十碳酸,其含量分别为其含量分别为4.08%、18.13%、11.48%、2.39%、0.87%、0.88%、1.04%、1.44%。      

超声微波双辅助提取葡萄籽低聚原花青素的研究

以新疆吐鲁番的赤霞珠葡萄籽为研究对象,利用超声微波双辅助法提取其中的低聚原花青素.以低聚原花青素提取率为考察指标,研究固液比、微波功率、微波辐照时间、作用次数、乙醇体积分数5个单因素对葡萄籽低聚原花青素提取率的影响.并采用响应面分析法对提取结果进行优化.结果表明,采用超声微波双辅助萃取技术得到的低聚原花青素提取率较单独采用超声或微波辅助得到的原花青素提取率高.在以70.3％vol的乙醇为提取溶剂、固液比为1∶14.6 (g∶mL)、超声处理30min、微波功率400W、微波时间30s的条件下,得到的低聚原花青素提取率最大为7.62mg/g.     

红花籽苯丙烯酰5-羟色胺衍生物的微波辅助提取和组分分析

研究了微波辅助提取红花籽中苯丙烯酰5一羟色胺衍生物的工艺条件,采用高效液相色谱-电喷雾质谱联用技术,对提取物进行了分析。通过单因素试验和正交试验,得出乙醇提取最佳工艺条件为：原料粒度20目、微波功率450W、回流温度65℃、微波辐射时间10min、液固比6：1（V/m）。在此条件下,得率达到1．36％,提取物纯度为43．91％。组分分析表明,微波辅助乙醇提取法可得到7种苯丙烯酰5-羟色胺衍生物,主要成分为阿魏酰-5-羟色胺、香豆酰-5-羟色胺。该法提取时间短,对苯丙烯酰5-羟色胺衍生物提取效率高,具有工业应用价值。     

Nutritional evaluation of ethanol extracted Madhuca (Madhuca butyraceae) seed flour

Defatted Madhuca flour is toxic due to the presence of saponins. Alcohol, 20–95%, was used to remove the saponins and it was found that two stage 60% ethanol extraction removed 90% of the saponins present in the flour. Rat feeding trials using the ethanol extracted flour at 10 and 15% protein levels yielded PER of 0.8 and 1.5 respectively and did not show any ill effects other than minor cytoplasmic vacuolation in liver and kidney in histological studies.     

The component acids of Carica papaya (caricaceae) seed oil

By the application of reversed-phase partition column chromatography, the oil from the seeds of Carica papaya was found to contain the following acids: lauric, 0.4%; myristic, 0.4%; palmitic, 16.2%; stearic, 5.0%; arachidic, 0.9%; behenic, 1.6%; hexadecenoic, 0.8%; oleic, 74.3%; and linoleic, 0.4%.     

微波和红外处理油茶籽对压榨油茶籽油中VE 含量的影响

以油茶籽为原料,研究微波和红外处理对压榨油茶籽油V_E中4种生育酚异构体含量的影响。结果表明:油茶籽毛油中α-生育酚含量较高(0.24～0.41 mg/g),β-、γ-、δ-生育酚含量低于检测限;油茶籽仁和油茶籽压榨毛油中α-生育酚初始含量存在一定差异;最佳处理条件为微波功率560 W,红外温度130℃;两种处理方式均加速了油茶籽中V_E的溶出和转化;微波处理比红外处理对α-生育酚影响更大。     

Physicochemical and functional properties of flour and protein isolates extracted from seinat (Cucumis melo var. tibish) seeds

The physicochemical and functional properties of seinat seed flour (SSF), defatted seinat flour (DSSF), and protein isolates were studied. Protein was extracted from DSSF using an alkali solution with isoelectric precipitation and freeze drying. Freeze dried seinat seed protein isolates (FSSPI), SSF, and DSSF were evaluated for their physicochemical and functional properties. SSF contained high levels of crude fat and fiber (31.13% and 24.75%, respectively). FSSPI contained 91.83% protein versus 28.58% for SSF. The amounts of potassium, the mineral with the highest content, were 9,548.33, 6,439.03, and 1,029 mg/100 g in SSF, DSSF, and FSSPI, respectively. The functional properties were variable among samples. The protein solubility of FSSPI was significantly higher (p<0.05) than for DSSF and SSF. FSSPI has a significantly better (p<0.05) foaming capacity, water/fat absorption capacity, and bulk density than SSF and DSSF. FSSPI also showed an emulsifying capacity comparable to commercial soy protein isolates.     

Chemical,physico-chemical and cytotoxicity characterisation of xyloglucan from Guibourtia hymenifolia (Moric.) J. Leonard seeds

A water-soluble polysaccharide was obtained from Guibourtia hymenifolia seeds in a 54.2% yield (w/w). The Glc:Xyl:Gal molar ratio was 3.3:2.3:1. The methylation results and 1D/2D NMR spectra indicated the presence of xyloglucan (XG), the intrinsic viscosity of which was 665 mL/g. The molar mass (M_w), radius of gyration (R_g), hydrodynamic radius (R_h), and ρ (R_g/R_h) of XG were 8.43 × 10⁵ g/mol, 97 nm, 61 nm, and 1.59, respectively, indicating a random coil and flexible conformation that was subsequently confirmed by the Mark–Houwink constant α (0.70). Atomic force microscopy analysis of XG adsorbed on silicon revealed that the chains are an average of 1.25-nm high, 28.9-nm wide and 131-nm long. Furthermore, a cytotoxicity assay indicated a high CC₅₀ value (>3.3 mg/mL). These results suggest that this biopolymer has potential applications in different food technologies and biotechnological processes.     

Effect of antioxidant principles isolated from mango (Mangifera indica L) seed kernels on oxidative stability of buffalo ghee (butter‐fat)

A method was developed to extract and isolate the antioxidant principles, ie mainly phenolic and phospholipid classes, from mango (Mangifera indica L) seed kernels using organic solvents. The presence of at least six phenolic compounds and eight phospholipids in the isolates was confirmed by chromatographic techniques. A phenolic preparation and a phospholipid preparation were prepared separately by dissolving the isolated compounds from mango seed kernels in buffalo ghee. The phenolic preparation contained 9.6 mg% water‐extractable phenolics, 69.5 mg% total phenolics and 6.39 mg% phospholipids. The phospholipid preparation contained 155.8 mg% phospholipids, 0.11 mg% water‐extractable phenolics and 0.19 mg% total phenolics. The addition of these preparations to buffalo ghee at 5, 10 and 20% levels individually and in combination significantly increased the levels of phenolics and phospholipids respectively. Samples of buffalo ghee with added BHA contained levels of these compounds similar to that of a control sample without any other additives. The antioxidant indices calculated from the induction period of ghee samples stored at 80 ± 2 °C. in comparison with the control were, in order, 10.11 (20% phospholipid and phenolic preparation) > 8.88 (10% phospholipid and phenolic preparation) > 8.66 (20% phenolic preparation) > 6.44 (5% phospholipid and phenolic preparation) > 5.44 (10% phenolic preparation) > 4.88 (20% phospholipid preparation) > 3.00 (5% phenolic preparation) > 2.77 (10% phospholipid preparation) > 2.22 (5% phospholipid preparation) > 1.44 (0.02% BHA). This demonstrated that the phenolics and phospholipids isolated from mango seed kernel, when added jointly to buffalo ghee, helped in extending the shelf‐life of ghee. © 2000 Society of Chemical Industry     

Equilibrium headspace analysis of volatile flavor compounds extracted from soursop (Annona muricata) using solid-phase microextraction

The influence of headspace solid-phase microextraction (HS-SPME) variables, namely, sample concentration, salt concentration and sample amount, on the equilibrium headspace analysis of the main volatile flavor compounds released from soursop was investigated. A total of 35 volatile compounds, comprising 19 esters, six alcohols, three terpenes, two acids, two aromatics, two ketones and an aldehyde, were identified. The results indicated that all response-surface models were significantly (p < 0.05) fitted for 10 target volatile flavor compounds. The results further indicated that more than 65% of the variation in the equilibrium headspace concentrations of target volatile flavor compounds could be explained by the final reduced models, with high R² values ranging from 0.658 to 0.944. Multiple optimization results showed that extraction using a 76.6% (w/w) sample concentration, 20.2% (w/w) salt and 8.2 g of blended soursop pulp was predicted to provide the highest overall equilibrium headspace concentration for the target soursop volatile flavor compounds.     

The characteristics of gelatin extracted from sturgeon (Acipenser baeri) skin using various pretreatments

The physicochemical characteristics of gelatin obtained by different pretreatments of sturgeon (Acipenser baeri) skin with alkaline and/or acidic solutions have been studied. Visual appearance, pH, gel strength, viscosity and amino acid profile of the gelatins were evaluated. Pretreatment with alkaline solutions of Ca(OH)₂ and/or acetic acid (HAC) provided gelatin with a favourable colour. Pretreatment with alkali removed noncollagenous proteins effectively, whilst acid induced some loss of collagenous proteins. Gel strength and viscosity of gelatin pretreated with HAC or alkali followed by HAC were as high as gelatin extracted in the presence of protease inhibitors. Amino acid composition had no significant effect on the gelatin characteristics. The total acid concentration for the highest gel strength was inversely proportional to ionisation strength, and the preferred pH for extracting gelatin with the optimum gel strength was approximately 5.0. The results showed that any available protons, regardless of the type or concentration of the acid, inhibit protease activity, which significantly affects the gelatin characteristics.