Effect of Roasting on the Chemical Composition and Protein Quality of Lupin Seeds (Lupinus albus cv Multolupa)

The effect of roasting lupin seeds (Lupinus albus cv Multolupa) for 10, 20, 30, and 40 min at 80–90°C was studied. Raw lupin was shown to be markedly deficient in the S-amino acids. These were not affected by roasting for 10 min, although a mild loss was observed for isoleucine and valine. However, heating for up to 40 min caused important losses in lysine and methionine + cystine. PER for raw lupin was 0.80 (casein 2.93) and that of the 10 min heated sample was 0.92 (NS), while roasting for 20, 30 and 40 min caused a severe reduction in protein quality (PER 0.59, 0.53 and 0.46 respectively). All these values improved significantly (p<0.01) by supplementation with 0.1% DL-methionine. Heating lupin seeds for 10 min may help to remove the “beany” flavor of this legume.     

Functional Properties of Lupin Seed (Lupinus mutabilis) Proteins and Protein Concentrates

Functional and electrophoretic properties of the seed flour and a protein concentrate prepared by alkaline extraction from lupin seeds (Lupinus mutabilis, cultivar H-6) were investigated. SDS-PAGE indicated presence of 13 and 12 subunits in the seed flour proteins and the protein concentrate, respectively. Lupin protein concentrate had good water and oil absorption and gelation properties. Solubility of lupin proteins was minimum at a pH of 4.0 but increased rapidly beyond pH 5.0. Foaming capacity of the protein concentrate could be improved by increasing concentration as well as by adding NaCl and was influenced by pH and incorporation of certain carbohydrates. Emulsion properties of lupin proteins were concentration and pH dependent. Moist heat improved the in vitro digestibility of the seed proteins. The seed flour as well as the protein concentrate did not have detectable trypsin, chymotrypsin, and α-amylase inhibitory activities.     

Sensory Evaluation and Acceptability of Cookies Enriched with Sweet Lupine Flour (Lupinus albus cv Multolupa)

Cookies enriched with 0, 5, 10, 15, 20, and 25% full-fat sweet lupine flour (FFSL) were evaluated by a sensory panel using the rank of preference and paired comparison tests. Cookies with 0, 5, and 10% FFSL were preferred while those containing 20 and 25% FFSL were rejected (p≤0.01). Studies conducted with school children showed similar acceptability for 0 and 10% FFSL-containing cookies which was different (p = 0.05) from those containing 20% FFSL. Fortification of the basic formula with 10% FFSL was recommended on the basis of acceptability.     

Nutritional quality of lupine (Lupinus albus cv. Multolupa) as affected by lactic acid fermentation.

The effects of selected NRRL strains of Lactobacillus acidophilus, L. buchneri, L. cellobiosus and L. fermentum upon oligosaccharide, phytate and alkaloid contents, as well as on the nutritive value of lupine, were investigated. Lupine was processed to a 12% total solids suspension, inoculated with 1% (v/v) cultures and fermented until a final desired pH of 4.5. L. acidophilus B-2092 and L. buchneri B-1837 growth was related to a significant sucrose breakdown and decreases of phytates, whereas L. acidophilus B-1910 and L. fermentum B-585 reduced the content of flatulence oligosaccharides. The activity of L. acidophilus B-1910 was particularly associated with lowering of alkaloids and increase of riboflavin. Lactic acid fermentation produced slight changes in lysine and methionine contents. No significant differences in net protein ratio values and protein digestibility were found between fermented and unfermented lupine (P less than 0.05). A 1:1 ratio mixture of B-1910 and B-2092 strains of L. acidophilus lead to a final fermented lupine with nutritional advantages to those given by the individual cultures.     

Bread quality and nutritional value of 'Marraqueta' and 'Hallulla' supplemented with full-fat sweet lupin flour (Lupinus albus cv. Multolupa)

'Marraqueta' and 'Hallulla' breads, widely consumed in Chile, were enriched with 6, 9 and 12% full-fat sweet lupin flour (FFLF) containing a small amount of alkaloids (0.025%) and 42.8% protein. Physical characteristics of the dough and the chemical composition and biological quality of the breads were investigated. Farinograph measurements showed that water absorption increased gradually from 61.3% for wheat flour to 79.8% for a blend with 12% FFLF. Developing time, weakening of dough and valorimeter value were not severely modified. Different levels of FFLF increased loaf weight as compared to all wheat bread. Protein content increased from 13.2% for the control to about 16% for 12% FFLF breads. Protein efficiency ratio (PER) values significantly increased (P < 0.01) for 12% FFLF breads: 'Marraqueta' from 1.10±0.09 to 1.59±0.12 and 'Hallulla' from 1.21±0.09 to 1.63±0.07. Apparent digestibility was about 86% and was not changed by FFLF inclusion up to 12%. Twelve per cent FFLF is a recommendable level to enrich 'Hallulla' and 'Marraqueta' in biological quality without affecting the farinological parameters. The results of acceptability tests will be published in due course.     

Functional Properties of Acylated Pea Protein Isolates

Pea protein isolates were acylated with succinic and acetic anhydride at 1.0, 3.0, and 5.0 mmol anhydride/g protein. The chemically modified isolates showed increased emulsifying capacity, emulsion stability, foam capacity and stability, and water adsorption compared to untreated pea protein isolate. In general, the greater the extent of acylation, the greater the improvement in emulsification properties compared to the untreated protein isolate; however, improvement at greater than 3.0 mmol anhydride/g protein was slight. Acetylation at 3 mmol/g increased foam capacity to the greatest extent. Water adsorption was enhanced to the greatest extent in protein isolates acetylated at 5 mmol/g. Acylation lowered the isoelectric point of protein isolates compared to untreated isolate. In vitro enzyme hydrolysis of the protein isolates, as determined by a multienzyme system of trypsin, chymotrypsin and peptidase, was not impaired by acylation.     

Functional Properties of Chinese Rapeseed Protein Isolates

A membrane-based protein isolation process developed in our laboratory produced two protein isolates from CH₃OH/NH₃/H₂O-hexane-extracted Chinese rapeseed meal. Both contained ～99% protein (NX6.25), and they were essentially free of glucosinolates or their breakdown products (<2,2 μmol/g). Their functional properties were evaluated and compared with a commercial soybean protein isolate. The precipitated isolate gave high values for all properties except nitrogen solubility index (NSI) while the soluble isolate showed excellent NSI and fat absorption but poor emulsification characteristics. They both had good foaming properties. The two Chinese rapeseed protein isolates complemented each other and were comparable to soybean protein isolate in most functions.     

Functional Properties of Deamidated Oat Protein Isolates

Oat protein isolates were deamidated by mild acid hydrolysis. Amino acid analysis and gel filtraiton chromatography showed no significant cleavage of peptide linkages although the aggregated and oligomeric oat proteins were extensively dissociated. Deamidation led to marked improvement in solubility, emulsifying properties and water and fat binding capacities. The pH for heat-induced gelation was lowered by deamidation, and a firm, elastic gel was produced by mixing egg white with deamidated oat isolates.     

Baking Studies and Nutritional Value of Bread Supplemented with Full-Fat Sweet Lupine Flour (L. albus cv Multolupa)

Full-fat sweet lupine flour (FFLF) was used to replace 3, 6, 9 and 12% of the wheat flour (WF) in bread. Physical characteristics of the dough, and the chemical composition and biological quality of the breads were investigated. Farinological studies showed that water absorption increased gradually from 60% for WF to 77% for a blend with 12% FFLF. Developing time, weakening of dough and valorimeter value were adversely modified by addition of FFLF. Different levels of FFLF increased in water absorption, loaf volume and loaf weight as compared to all wheat bread. However, specific loaf volume remained constant (3.72) up to 6% FFLF, then decreased. Protein content of wheat bread increased from 10.3% for the control to 11.7% for 9% FFLF bread. PER increased from 1.72 for the control bread to 2.00 for 9% lupine-bread (p<0.01). Bread with 9% FFLF is a possibility for using this legume in human feeding.     

Chemical Composition and Nutritional Quality of Sugar Cookies Containing Full-Fat Sweet Lupine Flour (L. albus cv Multolupa)

Full-fat sweet lupine flour (FFSL) (Lupinus albus cv Multolupa) containing 35.4% protein was used to enrich the cookies given to a group of school children. FFSL replaced 5, 10, 15, 20, and 25% of wheat flour in the formula. Farinological study, physical dough properties, chemical composition, and nutritional quality of cookies were studied. The protein content of the cookies increased by 8.9% up to 55.7% for the 5% and 25% FFSL, respectively. The highest PER (1.92) was found in cookies with 20% FFSL compared with 0.15 for the control. The results show a new area for application of FFSL in human diets.     

蛋白质氧化对乳清分离蛋白功能性质的影响

为了进一步研究蛋白质氧化对乳清分离蛋白(WPI)功能性质及流变学性质的影响,试验采用两种不同浓度的氧化系统H2O2(1 mmoL/L~20 mmoL/L)和FeCl3浓度(0.1 mmoL/L~2 mmoL/L)对WPI分别氧化1 h、3 h、5 h,测定其性质。结果表明:20 mmoL/L的H2O2氧化WPI 5 h,其乳化活性下降了50%以上;1 mmoL/L FeCl3氧化WPI 3 h,其凝胶硬度降低了94.5%;20 mmoL/L H2O2与1mmoL/L FeCl3氧化WPI 3 h,其弹性从0.976下降到0.713和0.721,分别降低了26.9%和26.1%;当H2O2浓度20 mmoL/L时,弹性模量从8154 Pa降到5399 Pa,复合模量从10890 Pa降到6653 Pa,分别降低了33.79%和38.91%;当FeCl3浓度为1 mmoL/L时,弹性模量从8154 Pa降到4935 Pa,复合模量从10890 Pa降到6049 Pa,分别降低了39.47%和44.45%。长时间高浓度的氧化条件使得蛋白质的空间结构受到严重影响,WPI的功能性质及凝胶质地发生较大的变化。因此,在实际生产中应尽可能地控制蛋白氧化的发生,减少其因为氧化所带来的营养损失或者降低其应用价值。     

Emulsifying and Foaming Properties of Different Protein Fractions Obtained from a Novel Lupin Variety AluProt‐CGNA® (Lupinus luteus)

The use of vegetable proteins as food ingredient is becoming increasingly important due to their high versatility and environmental acceptability. This work describes a chemical characterization and techno‐functional properties (emulsifying and foaming properties) of 3 protein fractions obtained from a protein‐rich novel lupin variety, AluProt‐CGNA^®. This nongenetically modified variety have a great protein content in dehulled seeds (60.6 g protein/100 g, dry matter), which is higher than soybean and other lupin varieties. A simple procedure was utilized to obtain 3 different fractions by using alkali solubilization and isoelectric precipitation. Fractions 1 and 3 were mainly composed of protein and polysaccharides (NNE), whereas fraction 2 was mainly composed by protein (97%, w/w). Fraction 3 presented interesting and potential foaming properties in comparison to the other fractions evaluated in the study. Besides, its solubility, foaming and emulsifying capacity were practically not affected by pH variations. The 3 fractions also presented good emulsion stability, reaching values above a 95%. SDS‐PAGE showed that fractions 1 and 2 contained mainly conglutin α, β, and δ, but in different ratios, whereas fraction 3 contained mainly conglutin γ and albumins. The results of this work will provide better understanding for the utilization of each protein fractions as potential ingredients in food industry.     

Haemagglutinating and Trypsin Inhibitor Activities of Lupin Seed (Lupinus angustifolius)

The phosphate buffer saline (PBS) extracts of defatted lupin seed flour showed haemagglutin activity only with trypsinized rabbit erythrocytes. The lectin tested in crude extracts showed specificity towards galactose and lactose. Heat stability studies of PBS extracts on incubation for 10 min showed no reduction of haemagglutinin activity in the temperature range 40°C to 80°C while no haemagglutination was observed when incubated at 90°C for 8 min. The trypsin inhibitor activity of flour extracts was 14.4 TUI/mg protein.     

低温冷冻条件对大豆分离蛋白功能性的影响

通过大豆分离蛋白（soybean protein isolate,SPI）冷冻前后功能性的变化,研究低温冷冻条件（料液比、冷冻温度、冷冻时间）对SPI功能性（保水保油性、乳化特性及质构特性）的影响。结果表明：在经过冷冻实验的样品中,随着SPI添加量的减小,其保水保油性、乳化性先增加后减小,当SPI料液比为1∶12时,其保水性、保油性、乳化稳定性、硬度和弹性均达到相对最大;冷冻温度为－18 ℃时,其保水保油性、乳化性、硬度和弹性相对最大,－20 ℃时,其乳化稳定性相对最好;随着冷冻时间延长,其乳化稳定性减小,冷冻3 d时,SPI的乳化稳定性相对最好,冷冻2 d时其保水性相对最大。和未经冷冻处理的原样品相比,经过冷冻处理的SPI,功能性明显减弱,其中保水保油性、乳化性、质构特性都小于未冷冻处理的SPI。     

南瓜籽蛋白质的制备及其功能性质研究

采用碱溶酸沉法制备南瓜籽分离蛋白,通过正交试验确定最佳的提取工艺条件,并对所制得的分离蛋白的部分功能性质进行研究。结果表明,南瓜籽分离蛋白提取的最佳条件为pH11.0、温度50℃、料液比1:30(m/V)、提取时间1.5h。此时提取率为85.52%,纯度为91.07%。南瓜籽分离蛋白的等电点在5.5 左右;吸水性和吸油性都在1.2～1.6g/g 左右;乳化能力在适宜pH 值达到80% 以上;起泡性则相对较弱。     

Sensory Acceptability of Foods Containing Australian Sweet Lupin (Lupinus angustifolius) Flour

ABSTRACT: Foods containing Australian sweet lupin ( Lupinus angustifolius ) flour (ASLF) were assessed by consumer panelists ( n = 54) in comparison to wheat flour (control) and defatted soy flour (DFSF) products. All ASLF products were rated in the acceptable half of the evaluation scale. General acceptability of ASLF chocolate chip cookies and breakfast bars was rated similarly to the control and DFSF variants ( P > 0.05). ASLF pasta was rated lower than control but higher than DFSF pasta ( P < 0.05), whereas ASLF addition reduced the general acceptability of muffins and bread ( P < 0.05) compared with the other variants. Some ASLF products appeared palatable whereas ASLF incorporation rate in others requires reduction.     

Effect of germination and fermentation on the antioxidant vitamin content and antioxidant capacity of Lupinus albus L. var. Multolupa

The present work studies the antioxidant capacity as well as the vitamin C and E contents of raw, fermented and germinated seeds of Lupinus albus L. var. Multolupa. Vitamin C was quantified by micellar electrokinetic capillary electrophoresis and vitamin E isomers by high performance liquid chromatography. The antioxidant capacity was determined by spectrophotometry and expressed as trolox equivalent antioxidant capacity (TEAC) and by liposome methods using phospholipids bilayers. Germination, in general, brought about an increase in the content of α-tocopherol, a decrease in the content of γ-tocopherol and did not affect the content of δ-tocopherol, which resulted in an increment in the vitamin E activity. Vitamin C increased sharply but gradually after germination. Fermentation caused a drastic reduction in the antioxidant vitamin content, vitamin C was not detected and tocopherol isomers decreased significantly. Germination processes caused a significant increase in antioxidant capacity (TEAC) of both hydrophilic and lipophilic extracts and fermentation produced slight changes or total reduction in TEAC, depending on process conditions. The peroxidation of egg yolk phosphatidyl-choline (PC) was inhibited by all lupin extracts in comparison with control assay. Germination was selected as a good treatment to increase antioxidant capacity and vitamin C and E contents.