Combining Aqueous Extraction and Membrane Isolation Techniques to Recover Protein and Oil from Soybeans

Two relatively new protein isolation techniques (the Aqueous Extraction Process and the Membrane Isolation Process) were combined to obtain a single isolation procedure to produce protein and oil food products from undefatted soybeans. Three lots of soybeans were processed using aqueous extraction, centrifugation and industrial ultrafiltration membranes to obtain either a full-fat, low-fat or intermediate-fat product and an oil cream. Proximate and amino acid analyses, nitrogen solubility profiles, and storage tests were made on spray dried products. Mean membrane permeation rates achieved ranged from 20–42.6 gfd. Protein products possessed high nitrogen solubilities below pH 3.5 and above pH 7, and were desirably light in collor.     

Properties of soluble protein powders from Alaska pollock (Theragra chalcogramma)

Soluble protein powders were produced from pollock by‐products and evaluated for their functional, nutritional and rheological properties. Soluble protein powders were made from pollock viscera (PVSP), viscera without liver (PVWLSP), heads (PHSP), frames (PFSP), trimmings (PTSP), and liver (PLSP) and had protein contents ranging from 65.0% to 78.9%. Yield of PVWLSP was higher than that of other pollock proteins powder and PTSP had the highest nitrogen solubility value (85.7%). Emulsion capacity and emulsion stability of the pollock protein powders ranged from 29% to 34.5% (mL of oil per 200 mg of protein) and 65.3% to 77.6%, respectively. Highest and lowest fat adsorption values were observed for PFSP (10.6 mL of oil per gram of protein) and PVSP (4.1 mL of oil per gram of protein), respectively. Fish protein powder samples were good sources in K, P, and Mg and amino acids. Emulsions made with pollock soluble protein powders exhibited viscoelastic characteristics.     

Extrusion of Pinto Bean High Protein Fraction Pretreated with Papain and Cellulase Enzymes

High protein fraction of pinto bean was pretreated with papain and cellulase enzymes and extruded at a temperature of 120°C. The effect of enzyme type and concentration, moisture and duration of incubation on expansion, texture, color, water absorption and solubility, pH, sugars, nitrogen solubility index and in vitro protein digestibility of the extrudate were investigated. Enzymatic modification had differential effects on nitrogen and carbohydrate components and on some physical and functional preperties of extrudates, depending on type of enzyme and incubation conditions. Results indicated the possibility of controlling protein and fiber hydrolysis at low moisture to obtain a desirable degree of modification to improve extruded products. This method may be used in food applications to obtain new snack type products from beans or their fractions.     

Effect of Partial Proteolysis and Succinylation on Functionality of Corn Germ Protein Isolate

Corn germ protein isolate (CGPI) was partially hydrolyzed with trypsin and pepsin and succinylated at three levels. Various functional and electrophoretic properties of the native and modified protein were determined. Water absorption and foaming properties of CGPI were Improved by partial hydrolysis with trypsin; emulsifying capacity and nitrogen solubility were reduced; oil absorption was increased only slightly. CGPI pepsin hydrolyzate has decreased oil absorption, nitrogen solubility and emulsifying capacity but improved foaming properties; water absorption was unchanged. Treatment of CGPI with succinic anhydride improved water and oil absorption, nitrogen solubility and foaming capacity but decreased emulsifying capacity; foam stability was unchanged. Succinylation retarded electropohoretic mobility while hydrolysis altered band intensities.     

Enzymatic and Autoxidation of Defatted Peanuts

Ground, blanched, raw, and roasted peanuts with varying oil contents were analyzed for oxidation products. Peroxide values (PV) of blanched, ground raw (BRAW) peanuts, demonstrating enzymatic oxidation, and heat-treated rancid roasted peanuts (RRST), demonstrating autoxidation, exhibited decreases (p ≦ 0.05) with decreasing oil content. The Oxidative Stability Index (OSI) time at 110 °C increased (p < 0.05) with decrease in oil content of raw (BRAW) and roasted (BRST) ground peanuts. A higher OSI indicated more oxidative stability, thereby supporting the hypothesis of higher potential for autoxidation at higher oil contents. In addition, BRST exhibited a shorter OSI than BRAW, indicating slower autoxidation in BRAW. Roasted peanutty odor, burnt odor, and roasted peanutty flavor, rancid/oxidized flavor, and burnt flavor scores of rancid roasted peanuts decreased (p ≦ 0.05) with decreasing oil content.     

新疆不同地区加工专用花生营养成分比较

花生生长条件和环境不同导致其品质出现差异,分析不同来源花生原料的品质有利于优化原料的选择,为花生产品加工利用提供参考。新疆南、北疆和东疆均有种植花生,但适合新疆不同地区种植的加工专用品种较少,采集新疆不同地区和内地3个省份的32个样品,对含油量、蛋白质、蔗糖、油酸/亚油酸（O/L）、蛋白亚基、氨基酸等6个指标进行测定、分析比较。结果表明,同一花生品种在不同地区种植后的营养成分含量存在一定差异,整体而言,新疆花生的含油量、蛋白质、蔗糖等指标在不同程度上优于内地,进一步分析得出花生在吐鲁番的含油量、O/L、伴花生球蛋白、总氨基酸含量最高,最高值为55.71%、35.11、37.39%、28.23 g/100 g,在阿拉尔的蛋白质、花生球蛋白含量最高,最高值为22.67 g/100 g、63.28%,在和田的蔗糖、23.5 ku亚基含量最高,为5.07 g/100 g、20.48%,在三坪的37.5 ku亚基含量最高（9.31%）。新疆不同地区不同品种花生的营养成分研究为新疆花生产业区域布局提供参考,为企业选择优质原料、建立原料基地提供依据。     

Effects of gamma irradiation dose and short-term storage on phytochemicals,antioxidants, and textural properties of boiled ‘Tainan 9’ peanuts

Boiled peanuts are preferable as a ready-to-eat healthy snack; however, gamma irradiation as a postharvest treatment of raw peanuts may induce unfavourable food components. Hence, the phytochemical, antioxidant, and the texture of boiled ‘Tainan 9’ peanuts pretreated with gamma irradiation (0, 2.5, 5, and 10 kGy) and stored at 29 ± 2 °C for up to 180 days were investigated. Both gamma irradiation and storage time contributed to testa darkening in raw peanuts. In boiled irradiated products, irradiation doses and storage time affected the moisture content (MC), total proteins, total oil, total soluble sugars, and antioxidant capacity (P ≤ 0.05). Total phenolic and flavonoid contents showed an increase at days 90 and decreased at days 180 across all treatments. A positive correlation was observed among ferric reducing antioxidant power (FRAP), total phenolics, and total flavonoids. Gamma irradiation at 10 kGy led to increase of peroxide value (PV) (P ≤ 0.05), but malondialdehyde (MDA) content was unaffected. Textural properties of boiled irradiated peanuts were soft. As a result, gamma irradiation at 5 kGy is recommended for postharvest treatment of raw peanuts with subsequent storage up to 180 days to obtain the eating quality of boiled peanuts with good phytochemicals and antioxidant properties, which is a challenge for food industry.     

Protein-based coatings on peanut to minimise oil migration

Soy protein isolate (SPI) or calcium caseinate (CC)-based coatings were applied on peanuts as a barrier of oil migration, and their efficiency was evaluated. These coatings induced a decrease of oil migration as compared to the uncoated peanuts. Subsequently, three polysaccharides were individually added to the coating solution to prevent oil migration further. The incorporation of carboxymethylcellulose (CMC) with SPI and CC coating solutions significantly (p ? 0.05) decreased the migration of oil as compared to the coatings without CMC. The addition of pectin seemed unfavourable because it enhanced the migration of oil. Starch in SPI-based coating solution helped to decrease the oil migration, but it did not affect the migration level in samples treated with CC solution. The results from size-exclusion chromatography showed strong cross-links by glutaraldehyde and transglutaminase treatments in SPI and CC-based coating solutions. A strong cross-linking in protein-based coating correlated closely with a reduction in oil migration. For both proteins, the cross-linking by transglutaminase was most efficient for improving the effectiveness of coating. This study demonstrated that our protein-based coatings can be effectively implemented to food industry for better quality of peanut products.     

Coating of Peanuts with Edible Whey Protein Film Containing α‐Tocopherol and Ascorbyl Palmitate

ABSTRACT: Physical properties of whey protein isolate (WPI) coating solution incorporating ascorbic palmitate (AP) and α‐tocopherol (tocopherol) were characterized, and the antioxidant activity of dried WPI coatings against lipid oxidation in roasted peanuts were investigated. The AP and tocopherol were mixed into a 10% (w/w) WPI solution containing 6.7% glycerol. Process 1 (P1) blended an AP and tocopherol mixture directly into the WPI solution using a high‐speed homogenizer. Process 2 (P2) used ethanol as a solvent for dissolving AP and tocopherol into the WPI solution. The viscosity and turbidity of the WPI coating solution showed the Newtonian fluid behavior, and 0.25% of critical concentration of AP in WPI solution rheology. After peanuts were coated with WPI solutions, color changes of peanuts were measured during 16 wk of storage at 25 °C, and the oxidation of peanuts was determined by hexanal analysis using solid‐phase micro‐extraction samplers and GC‐MS. Regardless of the presence of antioxidants in the coating layer, the formation of hexanal from the oxidation of peanut lipids was reduced by WPI coatings, which indicates WPI coatings protected the peanuts from oxygen permeation and oxidation. However, the incorporation of antioxidants in the WPI coating layer did not show a significant difference in hexanal production from that of WPI coating treatment without incorporation of antioxidants.     

粉碎处理对花生水酶法提取油脂和蛋白质的影响

研究花生粉碎程度对花生水酶法提取油脂和水解蛋白得率以及提油过程所得乳状液稳定性的影响。利用小型中药粉碎机在粉碎11次(8s/次)后将花生体积平均粒径减小到28μm,此时水酶法工艺的总得油率和水解蛋白得率最高,分别为88.8%和77.5%。当花生料浆的平均粒径降至28μm后继续粉碎,水酶法过程中会发生严重的乳化现象,且乳状液稳定性增加,导致总得油率和水解蛋白得率降低。     

富硒花生中含硒蛋白的提取及其抗氧化性的研究

脱脂富硒花生干粉(0.3147μg/g)的硒含量是普通花生脱脂干粉的2.5倍以上。富硒花生中蛋白质的提取率为23.39%,碱溶性蛋白是富硒花生中蛋白质的主要形式,蛋白含量占总可提取蛋白的92.82%,它结合的硒占总蛋白硒的77.33%,在富硒花生的不同溶解性的蛋白质提取物中,水溶性蛋白相比于其他蛋白提取物具有更高的DPPH自由基清除能力,更高的还原力和更长的诱导时间,这在很大程度上可以解释为由于它的高硒含量。     

大豆蛋白质原料体系对挤压组织化的影响

本文采用FTS-50型双螺杆挤压机,试验研究了复合大豆蛋白质原料体系中蛋白质含量、氮溶指数、油脂含量、淀粉含量和水分含量对挤压过程和产品组织化质量的影响研究结果表明,高蛋白质含量和高氮溶指数能促进挤压组织化作用,添加适量油脂和添加淀粉能促进挤压稳定性、组织质量和挤压产品的风味与口感,挤压产品(例如人造肉)的适当水分含量范围是60％—65％     

Physical properties of whey protein coating solutions and films containing antioxidants

ABSTRACT:  Antioxidants (ascorbyl palmitate and α-tocopherol) were incorporated into 10% (w/w) whey protein isolate (WPI) coating solution containing 6.67% (w/w) glycerol (WPI:glycerol = 6:4). Before incorporation, the antioxidants were mixed using either powder blending (Process 1) or ethanol solvent-mixing (Process 2). After the antioxidant mixtures were incorporated into heat-denatured WPI solution, viscosity and turbidity of the WPI solutions were determined. The WPI solutions were dried on a flat surface to produce WPI films. The WPI films were examined to determine transparency and oxygen-barrier properties (permeability, diffusivity, and solubility). WPI solution containing antioxidants produced by Process 1 and Process 2 did not show any difference in viscosity and turbidity, but viscosity was greater for the WPI solution with rather than without antioxidants. WPI films produced by Process 2 were more transparent than the films produced by Process 1. Oxygen permeability of Process 1 film was lower than Process 2 film. However, both the diffusivity and solubility of oxygen were statistically the same in Process 1 and Process 2 films. Both control WPI films and antioxidant-containing WPI films had very low oxygen solubility, comparable to polyethylene terephthalate films. Permeability of antioxidant-incorporated films was not enhanced compared to control WPI films.     

Characterization of Gamma Irradiated Peanut Kernels Stored One Year Under Ambient and Frozen Conditions

Peanut kernels were gamma irradiated at 0, 2.5,5.0,10, and 20 KGy, and stored 1 yr at ambient and frozen (? 14°C) conditions. Irradiated peanuts lost germination capabilities during storage. Molds were detected only on peanuts irradiated with 2.5 KGy and stored at ambient temperature. Peanut oil in kernels stored at ? 14°C was comparatively more stable than that in peanuts stored at ambient temperature. Oxidation of oil was not significantly changed by irradiation. Changes in fatty acid content varied slightly with exception of linoleic and linolenic acids which decreased with increased radiation depending on storage temperature. The SDS-PAGE protein patterns of peanuts revealed no noticeable variation of protein subunits resulting from irradiation and storage.     

Composition, stability and acceptability of different vegetable oils used for frying peanuts

The purpose of this work was to determine the chemical stability of vegetable oils in the frying process and the consumer acceptance of fried-salted peanuts prepared in different vegetable oils. Fatty acids composition was determined in sunflower, corn, soybean, peanut and olive oils. A chemical study (free fatty acid and p-anisidine values) of these oils at frying temperature (170 °C) was developed during 96 h. Consumer test of fresh products was performed on fried-salted peanuts prepared in the different oils. Peanut oil and virgin olive oil presented oleic acid as predominant fatty acid (44.8% and 64.2%, respectively), making it more resistant to lipid oxidation at frying temperature than the other refined vegetable oils (sunflower, corn and soybean oils). Virgin olive and peanut oils showed less increment of free fatty acids and p-anisidine value than the other oils along the heating essay. In addition, fried-salted peanuts prepared with refined peanut oil showed higher consumer acceptance than those prepared with other vegetable oils such as sunflower, corn, soybean and olive oils. Peanut oil could be used to fry peanuts obtaining products with higher consumer acceptance and shelf-life, thus preventing loss of their sensory and nutritional quality.     

Production of Peanut Flour from Microwave Vacuum-Dried Peanuts

Defatted peanut flours with significantly reduced raw peanut taste and nitrogen solubility of 85+% were produced from field Runner peanuts that had been microwave-vacuum-dried to maximum temperatures of 80°C and 96°C. The flours were prepared from 4.54 kg of peanuts, dried from 25.5% to less than 10% moisture, at 375 Torr absolute pressure and at 1400 and 813 watts microwave power (2450 MHZ). Peanut temperature at end of drying significantly affected the intensity of the raw peanut flavor. Storage at 23.9°C for 14 months had no significant effects on intensity of the raw peanut flavor. Hexane extraction of blanched peanut kernels showed that mass velocity percolation rates increased with increase in final drying temperature of peanuts.     

Physico-Chemical Properties of the Flour, Protein Concentrate, and Protein Isolate of the Cupuassu (Theobroma grandiflorum Schum) Seed

ABSTRACT:  Defatted flour, protein concentrate, and protein isolate obtained from Amazonian cupuassu seeds were evaluated for their solubility properties, water and oil retention capacity, foam formation and stability, gelling properties, emulsifying ability, and emulsion stability. The protein contents of defatted flour, the concentrate, and the isolate were 27.65%, 31.18%, and 64.29%, respectively. As expected, the protein isolate exhibited higher solubility than the protein concentrate, achieving more than 90% solubility at pH 8.0. The flour and the protein concentrate, however, showed excellent water and oil retention capacities. High emulsifying capacity at pH 7.0 was also observed for all 3 products: 987 mL oil/g, 977 mL oil/g, and 1380 mL oil/g for the flour, protein concentrate, and protein isolate, respectively. Gelling properties were not exhibited by any of the products, but all of them exhibited good utilization potential, not only to enrich other foods but also to enhance relevant functional properties.     

Recovery of proteinaceous substances from chicken heads by proteolysis with trypsin

Trypsin was used to hydrolysis of chicken heads under various conditions. It was found, using response surface methodology, that hydrolysis conducted at 60 °C following the addition of 750 g water and 2.5 g enzyme per kg raw material yielded after 4 h 88 g of dry hydrolysate containing 83% protein which amounts to 50.7% of nitrogen recovery. The final freeze-dried product was cream coloured, had flavour typical for poultry products and was of high microbiological quality. Its nutritive value was limited by sulphurous amino acids (chemical score = 70.9). It also revealed good solubility in water (Nitrogen solubility index [NSI] = 94.1). The obtained hydrolysate may be useful as a protein fortification agent for concentrated soups as well as a component of seasonings and other food products.     

我国花生及花生产品出口结构与竞争力分析——基于1997-2007年进出口贸易数据

本文从出口产品结构、出口市场结构、出口的国内地区分布三方面分析了我国近11年来花生及花生产品的出口贸易结构,并运用国际市场占有率、贸易竞争指数、显示性比较优势指数对我国花生及花生产品的出口竞争力进行了测算和比较分析。结果表明：我国在花生果、花生仁、花生制品等劳动密集型产品上的优势很明显,竞争力很强,而在花生油和花生粕等资本密集型产品上的国际竞争力较弱。