Physicochemical and functional characterization of by-products from chia (Salvia hispanica L.) seeds of Argentina

The objective of this study was to characterize the physicochemical and functional properties of meals (M) and fibrous fractions (FRF) of chia seeds (Salvia hispanica L.), and to compare the effect of oil extraction methods (pressing -p- and solvent extraction -s-) and sieving process on these properties. Both processes affect the physicochemical and functional properties of residual meals and their corresponding fibrous fractions. Mp and FRFp showed a significantly higher residual oil content than Ms and FRFs (11.39, 10.85, 0.21 and 0.21 g/100 dry base, respectively). The sieving process of both meals allowed to obtain fibrous fractions with a significant increase of crude fiber (27.57, 32.84, 23.81 and 28.35 g/100 g in Ms, FRFs, Mp and FRFp, respectively), and a marked decrease of protein content (41.36, 35.32, 35.00 and 33.74 g/100 g in Ms, FRFs, Mp and FRFp, respectively). Total dietary fiber and their respective components (soluble and insoluble dietary fiber) were significantly higher in FRF. All the samples exhibited a high antioxidant activity due to the presence of phenolic compounds and tocopherols in the case of Mp and FRFp. Ms and FRFs presented a better oil-holding capacity, organic molecule absorption capacity, emulsifying activity and emulsion stability than Mp and FRFp, and allowed to achieve more stable emulsions. FRFs showed the highest values of water absorption and adsorption capacity.     

番木瓜籽蛋白质的提取工艺及其功能性质

以番木瓜籽为原料,经脱脂以酸沉碱溶法提取其中的蛋白质,并研究其乳化、起泡等功能性质。结果表明,最佳的提取工艺条件:料液比1∶40,p H为9.3,温度50℃,碱提时间120 min时最高提取率达到48.53%。番木瓜籽蛋白质的乳化性及稳定性随着蛋白质的浓度升高而升高,在p H3时最小,其乳化性在Na Cl浓度为0.2%时最大,而稳定性呈下降趋势;起泡性及稳定性随蛋白浓度升高而升高,在p H3.0,其起泡性和泡沫稳定性最小,在离子浓度(Na Cl)为0.2 mol/L时,其起泡性和泡沫稳定性最高。可见,此提取工艺效果较好,能将部分番木瓜籽蛋白质提取出来;番木瓜籽分离蛋白质乳化性和起泡性良好,这为番木瓜籽蛋白质的开发利用提供参考依据。      

Influences of ultrasonic treatment on structure and functional properties of salt-soluble protein from Moringa oleifera seeds

Influences of ultrasonic treatment on structure and functional properties of salt-soluble protein from Moringa oleifera seeds (MOSSP) were explored. The results indicated that the ultrasonic treatment destroyed spherical structure of MOSSP and transformed the spherical structure into irregular fragments. The content of β-turn, α-helix and random coils in MOSSP significantly increased, but with extending the ultrasound time, the content of β-turn, α-helix and random coils had no significant change. SDS-PAGE results showed that sonication could stabilise the primary structure of MOSSP. The surface hydrophobicity and emulsification were significantly reduced, but sonication could improve the solubility and foaming properties of MOSSP within a certain range.     

Food hydrocolloids as additives to improve the mechanical and functional properties of fish products: A review

The restructuring process offers to fish processors the opportunity to obtain new products, taking advantage of both low-value fish species and remains from filleting and other processing operations. However, mechanical and functional properties of restructured products depend on the biochemical and physicochemical properties of muscle proteins, mainly myosin and actomyosin. In this regard, the biochemistry of fish muscle is different from that of mammals and birds. Therefore, fish products must be processed in a different way from red meat or poultry. The main fish products are surimi and restructured products. Fish products can be improved or modified by using hydrocolloids (carbohydrates and protein) as additives. In this review, the modern technology to obtain these products, the applications of hydrocolloids in fish products, and the implications of the increasing demand for healthy, low-salt fish products are discussed.     

Physicochemical characterization and functional properties of galactomannans from mesquite seeds (Prosopis spp.)

In the present study, the physicochemical and functional characteristics of galactomannans (GM) from mesquite seeds were investigated and compared with the characteristics of a commercial GM. The mesquite gum was extracted with water at room temperature, and its physicochemical parameters, thermal constants and functional properties were determined. The results showed that mesquite GM had contents of 2.56% moisture, 4.54% protein and 0.06% ash; trace levels of fat; 95.40% total carbohydrate; +63.48 optical rotation; an intrinsic viscosity of 12.36 dL/g and a molecular weight of 1.2 × 10⁶ g/mol. The sugars detected were mannose (Man) and galactose (Gal), with a Man:Gal ratio of 1.50. The curves obtained by calorimetry indicated a transition temperature (Tg), melting temperature (Tm) and heat capacity (Cp) very similar to those of the guar GM. The evaluation of the functional properties of the mesquite GM revealed a solubility of 92.10%, an emulsion capacity of 95% and an emulsion stability of 92.24%. The polysaccharide extracted from the mesquite seeds is a GM with physicochemical and functional properties similar to those reported for other legume seed gums, allowing us to conclude that mesquite GM has the potential for use in the food industry.     

Composition and functional properties of raw and electron beam-irradiated Mucuna pruriens seeds

The proximate, nutritional and functional properties of raw and electron beam-irradiated (0–30 kGy) Mucuna seeds were investigated. Irradiation increased crude protein and crude carbohydrates significantly than crude lipid, crude fibre and energy. Raw seeds were rich in minerals and were not affected by irradiation except for magnesium and phosphorus. Amino acids of raw seeds were comparable to soyabean and FAO/WHO reference pattern and except for 30 kGy, no significant changes were seen in amino acid profile. Raw seeds were rich in unsaturated fatty acids and some of them decreased on irradiation, while linoleic acid steadily elevated (0–14.35 mg g⁻¹ lipid). In vitro protein digestibility was dose dependent and significantly increased up to 15 kGy. Water and oil absorption capacities and foaming capacity significantly increased on irradiation, while protein solubility decreased (15 and 30 kGy) with an improvement of gelation property of seed flour. The cooking time of seeds significantly reduced on irradiation.     

Physicochemical and functional properties of whole and defatted meals from Mexican (Cucurbita pepo) pumpkin seeds

Chemical composition and some functional and thermal properties in whole pumpkin seed meal (WPSM) and defatted pumpkin seed meal (DPSM) were determined. The DPSM exhibited higher water absorption capacity (3 g H₂O per g sample), water solubility capacity (8.75%), oil absorption capacity (2.73 g oil per g sample), emulsifying capacity (61.71%), foaming capacity (51.92%) and gelling capacity (12% w/v) than the WPSM. The DPSM also had better swelling power (3.33% at 60 °C, rising to 4.31% at 90 °C), higher phase transition temperatures (T₀ = 80.04 °C, T_p = 86.50 °C and T_f = 93.20 °C) and a higher phase transition energy (0.93 J g^?1). However, the WPSM had higher bulk density (0.57 g cm^?3) and better foam stability (from 30 to 120 min). Micrographs showed defatting to cause microstructural changes in meal starch granules and proteins. Its high protein content makes the DPSM a potential alternative input in the food industry.     

平欧榛子蛋白分离及功能特性分析

为了充分利用平欧榛子资源,提高附加值,采用Osborne蛋白分级法及聚丙烯酰氨凝胶电泳提取并分析了其蛋白质组分和相对分子质量分布。采用碱溶酸沉法提取其分离蛋白并对分离蛋白的功能特性进行了检测和分析。结果表明:清蛋白占榛子粗蛋白的67.18%,球蛋白占17.62%,谷蛋白占6.53%,醇溶蛋白占3.17%;还原和非还原聚丙烯酰氨凝胶电泳(SDS-PAGE)分析表明,榛子蛋白质各组分中均存在二硫键,非还原条件下,各组分亚基相对分子质量主要分布在35⁷1 kDa,还原条件下,各组分亚基相对分子质量主要分布在1671 kDa,还原条件下,各组分亚基相对分子质量主要分布在16⁵0 kDa且均有2条明显的亚基带;分离蛋白功能特性研究显示,pH值在等电点附近榛子蛋白的溶解性、持水性、起泡性和乳化性最低,而泡沫稳定性在等电点附近有最大值,50℃时持水性最高,而吸油性在50℃时最低为2.815 g/g。     

Polyphenols from Stevia rebaudiana (Bertoni) leaves and their functional properties

The major polyphenol components from Stevia rebaudiana (Bertoni) leaves (PPS) are chlorogenic acids, a polyphenol family of esters, including hydroxycinnamic acids with quinic acid, which possesses excellent hydrophilic antioxidant activity and other therapeutic properties. As an abundant byproduct during production of steviol glycosides, the PPS would be a new antioxidantive food resource or additives applied in foods and drugs with antidiabetic function. Extracting PPS from S. rebaudiana (Bertoni) leaves together with steviol glycosides would be an economic process, which will change most operation process in current Stevia factories. The quantification of PPS needs to be unified for regulation. In view of the current regulation status of polyphenols and extracts from Stevia, the PPS would be ready to go to the market with few regulation barriers in the near future. This review will summarize the analysis, extraction, and some functional properties of PPS, such as antioxidant, antidiabetic, antimicrobial, anti-inflammatory, and anticancer.     

Polyphenols from longan seeds and their radical-scavenging activity

Five previously uncharacterised polyphenols, ethyl gallate (2), 1-β-O-galloyl-d-glucopyranose (3), methyl brevifolin carboxylate (4), brevifolin (5) and 4-O-α-l-rhamnopyranosyl-ellagic acid (8), and three previously identified polyphenols, gallic acid (1), corilagin (6) and ellagic acid (7), were isolated from longan seeds. Their structures were identified by spectroscopic and chemical methods including HRESIMS and NMR. Eight polyphenols exhibited scavenging activity towards DPPH radicals with SC₅₀ values of 0.80–5.91 μg/ml and towards superoxide radicals with SC₅₀ values of 1.04–7.03 μg/ml. The radical-scavenging activity of the newly characterised polyphenols was comparable to that of gallic acid, corilagin and ellagic acid.     

玉米醇溶蛋白的超声辅助酶法提取工艺 及不同提取方法对其结构和功能特性的影响

以玉米蛋白粉为原料,对超声辅助α-淀粉酶提取玉米醇溶蛋白的工艺条件进行探究,并研究了超声波法、α-淀粉酶法、超声辅助α-淀粉酶法和醇法对玉米醇溶蛋白功能特性和结构的影响。结果表明：超声辅助α-淀粉酶法在超声功率密度2.85 W/cm3、超声时间35 min、超声温度45 ℃、酶添加量0.9%、酶解pH 6.0时提取的玉米醇溶蛋白蛋白质含量最高,为80.09%,显著高于超声波法(68.49%)和α-淀粉酶法(76.37%)提取的玉米醇溶蛋白;与醇法相比,超声辅助α-淀粉酶法、超声波法和α-淀粉酶法玉米醇溶蛋白的持水/持油力和乳化活性显著提高,溶解度和粒径减小,玉米醇溶蛋白二级结构更舒展,紫外吸收增强,内源荧光最大吸收峰发生红移,巯基含量升高,二硫键含量显著降低;不同提取方法对玉米醇溶蛋白的相对分子质量影响不大。     

超声辅助均相离子液体微萃取-高效液相色谱法测定丹参中的丹参酮

建立超声辅助均相离子液体微萃取-高效液相色谱法(UA-HILME-HPLC)同时测定丹参中的二氢丹参酮、丹参酮Ⅰ、隐丹参酮和丹参酮ⅡA。本研究以水溶性离子液体为萃取剂,以水为传递介质,采用超声波辅助提取目标物,通过向提取液中加入离子对试剂形成水不溶性离子液体,离心后发生相分离,取离子液体部分进行高效液相色谱分析。实验结果表明,超声辅助均相离子液体微萃取法的最佳提取条件为:以140μL[C8MIM][BF4]为萃取剂,以1 m L 0.6 mol/L NH4PF6溶液为离子对试剂,样品溶液p H 5.0,初始提取温度50℃,超声提取时间5 min,超声功率200 W。各目标化合物在线性范围内呈现良好的线性关系(r0.9996),检出限和定量限分别为0.02~0.04μg/m L和0.07~0.13μg/m L,日内和日间精密度(RSD)分别低于3.23%和4.57%,样品加标回收率在83.50~96.23%之间。本法集提取、浓缩、分离和纯化为一体,不使用挥发性有机溶剂,具有提取时间短,样品用量少等优点,可广泛应用于药用植物中活性成分的提取分析。     

Characterization of potato starch fractions and their interaction with hydrocolloids

Commercial potato starch was separated through sedimentation into three fractions of the size < 25, 25–70 and >70 µm estimated with the laser particle meter method and <21.6, 21.7–30.6 and >30.7 µm according to the Sartorius balance method. Amylose and amylopectin content in particular fractions did not depend on the granule size. Number average and weight average molecular weight slightly decreased and phosphorus content increased with the size of granules in the fractions. Starch fractions and, for comparison, non‐fractionated starch were gelatinized in aqueous solutions of arabic, carob, karaya and xanthan gums and carrageenan. Except for the arabic gum, all tested hydrocolloids decreased onset temperature of gelation, T₀, of all starch fractions. Carob and xanthan gums and carrageenan the most remarkably decreased that parameter for large fraction, whereas other gums most considerably decreased T₀ of starch of the medium fraction. Effect of gums upon such parameters of the characteristics of gelation as η_max, η_min and η_25°C depended irregularly on the size of starch granules. In gels from gums and small granules, the role of G′ and G″ module differed from that in gels from the other starch fractions.     

Ultrasound-assisted extraction and modification of plant-based proteins: Impact on physicochemical,functional, and nutritional properties

Ultrasonication is a green technology that has recently received an enormous research attention for extraction of plant-based proteins and tailoring the functionalities of these ingredients. Ultrasonication is generally used as a pretreatment method in the conventional protein solubilization protocols because it can break the cell matrix to improve the extractability. The rate of protein extraction and increase in the extraction yields depend on operating conditions such as sonic energy density, time of sonication, the substrate to slurry ratio, agitation, and so on. Ultrasonication is also applied to modify the physical, structural, and functional properties of protein-based ingredients, besides simultaneous extraction and modifications. Significant changes that occur in protein physical properties due to sonication include size reduction, rheology, electrical conductivity, and zeta (ζ) potential. These changes are due to cavitation-induced shear leading to changes in secondary and tertiary structures, including protein aggregation and cross-linking due to oxidation. Physical and structural changes affect the resulting ingredient functionality and nutritional quality of protein. Changes in the functional properties, especially hydrophobicity, solubility, emulsion, and foaming, depend on the extent of ultrasound energy applied to the protein. This study aims to review major ultrasound process parameters and conditions for extraction and modification of plant proteins and their impact on protein structural changes and resulting physicochemical, functional, and nutritional properties.     

响应面法优化丹参叶总酚酸超声波辅助提取工艺

对丹参叶总酚酸的超声提取工艺优化进行研究。在单因素试验基础上,选择提取溶剂乙醇体积分数、提取时间、温度和液料比为自变量,以丹参叶总酚酸得率为响应值,采用Box-Behnken试验设计方法,研究各自变量及其交互作用对丹参叶总酚酸提取率的影响。利用Design Expert软件得到回归方程的预测模型并进行响应面分析,确定超声波辅助提取丹参叶总酚酸的最佳条件为乙醇体积分数63.00%、浸提时间43.00min、温度50.00℃、液料比33:1(mL/g),在此条件下,总酚酸提取率达到7.78%。验证实验表明,所得模型方程能较好地预测实验结果。     

The isolation of volatile oil from cumin seeds by steam distillation

The isolation of the essential oil of cumin seeds by steam distillation is described. The chemical composition of the oil is investigated by means of chromatographic-spectrometric methods and physico-chemical indices. The 17 most important components are identified and quantified.     

Physical properties,chemical characterization and fatty acid composition of Mexican chia (Salvia hispanica L.) seeds

Chia seeds were utilized by Aztecs as food and for medicinal purposes. Nowadays, this crop is gaining importance in many countries, due to its nutritional attributes. Some physical properties and chemical characteristics of chia seeds from four different regions of Mexico were evaluated and compared. Seed size distribution was not significantly affected (P > 0.05) by the region, with similar values of seed length (2.03–2.10 mm), width (1.27–1.32 mm), thickness (0.77–0.81 mm) and surface area (4.95–5.42 mm²). Bulk density (662–741 kg m^?3), geometry and granulometric distribution were also determined. Origin of tested seeds significantly (P < 0.05) influenced their composition; all seeds had high contents of protein (18.5–22.3%), fat (21.5–32.7%) and fibre (20.1–36.1%). Chia seeds ratio between omega‐3 and omega‐6 fatty acids was 3:1 for the studied regions; seeds from Chiapas and Michoacán had the highest proportion of ω‐6 and ω‐3 fatty acids. The studied seeds contained phenolic compounds in the range of 0.53–0.71 mg GAE g^?1.