Nutritional and functional properties of Vicia faba protein isolates and related fractions

The goal of this research was the characterisation of Vicia faba (broadbean) protein isolates and related fractions in order to determine whether this grain legume could be used for production of high quality protein products and other fractions rich in functional components. Alkaline extraction of the defatted seed flour, followed by precipitation at the isoelectric pH, yielded a 92% protein isolate with a high oil absorption capacity. The contents of the favism-inducing glycosides, vicine and convicine, in the isolate were reduced by more than 99% as compared to the original flour, although the amino acid composition was similar to that of the flour. Some of the by-products of protein isolate production may also be of interest from a nutritional and functional point of view. Thus, the oil resulting from hexane extraction of the flour is rich in unsaturated fatty acids, and polyphenols (resulting from extraction of the defatted flour with acetone) showed a high ABTS radical-scavenging activity. In addition, the solid residue (resulting from protein solubilisation) was high in fibre and showed good water absorption. These results show good nutritional and functional properties in V. faba protein isolates and related fractions, which may favour the revalorisation of this traditional bean crop.     

Lupinus angustifolius protein isolates: chemical composition,functional properties and protein characterization

Two types of protein isolates were prepared from Lupinus angustifolius defatted flour by alkaline extraction, with (Isolate B) and without (Isolate A) sodium sulphite, and acid precipitation of proteins at the isoelectric point (IEP 4.3). Chemical composition, main functional properties and protein composition of L. angustifolius defatted flour and protein isolates were determined. Isolate A and B have 93.9 and 84.6% protein content, respectively, and had a balanced composition of essential amino acids, with respect to the FAO pattern except for lysine. The in vitro protein digestibility ranged between 86.3 and 93.9% for isolate A and B, respectively.     

Fatty acids composition and rheology properties of wheat and wheat and white or brown rice flour mixture

Manufacturing of bread from rice flour only presents technological difficulty because the rice is gluten-free and gluten is the most important structure forming protein. By using wheat and rice flour mixture, this problem can be avoided, and end product is enriched by rice-oil constituents. In this paper fatty acids composition, with an emphasis on total saturated, and total unsaturated fatty acids, rheological and baking properties of wheat–rice flour mixture (70:30 w/w) were investigated. The results show that wheat–rice flour mixture has better fatty acids composition with higher content of stearic, arachidic, lignoceric, oleic, and phthalic acids compared to wheat flour. Also, wheat flour did not include myristic, arachidic, lignoceric and linolenic acids, so rice flour addition made fatty acids profile richer as number of constituents is higher, nine instead six. The content of total unsaturated fatty acids content was higher in wheat–brown rice flour mixture than in wheat flour and in wheat–white rice flour mixture. When rice flour was added to wheat flour the rheological properties were changed: flour mixture had less water absorption, less degree of softening, longer development time, higher gelatinization temperature, but better stability and finally, better quality number and group than wheat flour. So, the wheat and rice flour mixture can be considered as a good quality flour and can be used for making good quality wheat-rice bread and cake.     

Taste Panel Preference Correlated with Lipid Composition of Barley Dried Distillers' Grains

Milled barley dried distillers' grains (DDG), bleached DDG, defatted DDG and bleached, defatted DDG were added to oatmeal cookies at 15% flour replacement levels. Sensory evaluation indicated that defatting significantly improved the acceptability of both DDG and bleached DDG. A consumer panel found oatmeal cookies and cookies containing defatted DDG to be equally accpetable followed, in decreasing order of preference, by cookies containing DDG, blanched, defatted DDG and bleached DDG. Thin-layer chromatography and gas liquid chromatography indicated that, compared to literature values for barley, DDG and bleached DDG contained increased quantities of free fatty acids (FFA) and reduced amounts of unsaturated fatty acids in both the FFA and triacylglycerol fractions.     

The effect of ethanol and specific growth rate on the lipid content and composition of Saccharomyces cerevisiae grown anaerobically in a chemostat

The effects of produced ethanol and specific growth rate on the lipid content and composition of Saccharomyces cerevisiae CBS 2806 were studied using anaerobic chemostat cultures. The cells adapted to increased concentrations of produced ethanol by increasing the proportion of ergosterol at the expense of lanosterol, by increasing the proportion of phosphatidylinositol at the expense of phosphatidylcholine, and by increasing the amount of C_18:0 fatty acids in total phospholipids at the expense of C_16:0 fatty acids. The produced ethanol had no effect on the phospholipid content nor on the proportion of unsaturated fatty acids in the phospholipids. The specific growth rate had no effect on the phospholipid content, the sterol composition, the phospholipid composition, the fatty acid composition of total phospholipids, or on the proportion of unsaturated fatty acids in the phospholipids of S. cerevisiae. It was not possible to separate the effects of produced ethanol and growth rate on the ergosterol content of the chemostat-grown S. cerevisiae cells.     

Supercritical fluid extraction and characterization of lipids from algae Scenedesmus obliquus

Supercritical carbon dioxide (SC-CO2) extractions (with and without ethanol as an entrainer) were carried out to remove lipids and pigments from protein concentrate of green algae (Scenedesmus obliquus) cultivated under controlled conditions. The content and fatty acid composition of algal lipids using column, thin-layer (TLC) and gas-liquid chromatography (GLC) were determined. Absorption spectra of extracted fractions showed the predominance of chlorophyll A (lambda max at 410 nm). Single step supercritical carbon dioxide (SC-CO2) extraction resulted mostly in removal of neutral lipids and a part of glycolipids, but phospholipids were not extracted. Addition of ethanol to SC-CO2 increased the amount of glycolipids and phospholipids in the extract. TLC pattern of algal lipids showed that the main part of neutral lipids consisted of diglycerides, triglycerides, hydrocarbons, free sterols, and sterol esters. The glycolipids were mostly monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. In phospholipids, phosphatidyl choline, phosphatidyl glycerol, and phosphatidyl ethanolamine were the main compounds. Fatty acid composition patterns indicated the main fatty acids to be 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2, and 18:3(a). Relatively high recovery of polyunsaturated fatty acids and essential fatty acids in supercritical fluid extracted algal lipids and proteins isolates were observed.     

Supercritical fluid extraction and characterization of lipids from algae scenedesmus obliquus

Supercritical carbon dioxide (SC‐CO₂) extractions (with and without ethanol as an entrainer) were carried out to remove lipids and pigments from protein concentrate of green algae (Scenedesmus obliquus) cultivated under controlled conditions. The content and fatty acid composition of algal lipids using column, thin‐layer (TLC) and gas‐liquid chromatography (GLC) were determined. Absorption spectra of extracted fractions showed the predominance of chlorophyll A (λ_max at 410nm). Single step supercritical carbon dioxide (SC‐CO₂) extraction resulted mostly in removal of neutral lipids and a part of glycolipids, but phospholipids were not extracted. Addition of ethanol to SC‐CO₂ increased the amount of glycolipids and phospholipids in the extract. TLC pattern of algal lipids showed that the main part of neutral lipids consisted of diglycerides, triglycerides, hydrocarbons, free sterols, and sterol esters. The glycolipids were mostly monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. In phospholipids, phosphatidyl choline, phosphatidyl glycerol, and phosphatidyl ethanolamine were the main compounds. Fatty acid composition patterns indicated the main fatty acids to be 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2 and 18:3(a). Relatively high recovery of polyunsaturated fatty acids and essential fatty acids in supercritical fluid extracted algal lipids and protein isolates were observed.     

Effect of lipoxygenase activity in defatted soybean flour on the gelling properties of soybean protein isolate

Soybean lipoxygenase was inactivated to different degrees by dry heating of defatted soybean flour for 0, 5, 10, 15, 20 and 25 min and soy protein isolates were prepared thereof by isoelectric precipitation of the water extract of the defatted soybean flour. The fluorescence emission intensity at 420 nm of the chloroform–methanol extract of soy protein isolates, which was indicator of the existence of peroxidized lipid, varied in parallel with the lipoxygenase residual activity in defatted soybean flours. The dispersion of soy protein isolate showed an increasing turbidity with the increase of lipoxygenase residual activity in the starting defatted soybean flour, suggesting an elevated tendency to form insoluble aggregates during the preparation of soy protein isolate. Small deformation rheological test revealed that the gelling times were shorter for those soy protein isolates derived from low lipoxygenase activity defatted soybean flours than that of high lipoxygenase activity. Frequency sweep showed that G′ of soy protein isolate derived from low lipoxygenase defatted soybean flour was independent of oscillation frequency in contrast to that of derived from non dry-heated defatted soybean flour, the latter showed a marked frequency dependence. Large deformation test revealed that the gel hardness increased about 10 times after dry heating of defatted soybean flour for 20 min. As the increase of the lipoxygenase residual activity, the gel permeability increased markedly, suggesting that soy protein isolate from high lipoxygenase defatted soybean flour produced coarser textured gel, which corresponded well with the results of scanning electron microscopy.     

不同方法制备的美藤果油品质研究

对美藤果成分进行了分析,并对乙醚萃取、超临界CO_2萃取以及压榨制备的美藤果油的品质进行研究。结果表明:美藤果全籽粗脂肪含量为32.88%,美藤果仁粗脂肪含量为51.86%,美藤果仁中粗蛋白质含量为23.23%;3种方法制备的美藤果油皂化值、碘值以及脂肪酸组成和含量并无明显的差异,均含有较高的不饱和脂肪酸(92%),且以亚麻酸和亚油酸为主;美藤果油中生育酚主要为γ-生育酚和δ-生育酚;超临界CO_2萃取和乙醚萃取的美藤果油中甾醇和生育酚含量稍高于压榨美藤果油,其中超临界CO_2萃取的美藤果油中生育酚含量较高,乙醚萃取的美藤果油中游离态甾醇和酯态甾醇含量较高。     

Macadamia oil extraction methods and uses for the defatted meal byproduct

BackgroundThe trend towards the consumption of functional foods that aid in the maintenance of human health has increased in recent decades. In this way, macadamia nut contains bioactive compounds and high levels of monounsaturated fatty acids that are beneficial to health and can be minimally processed or industrialized for the production of oil and defatted flour.Scope and approachThe extraction of macadamia oil is commonly performed by cold pressing; however, the process presents low extraction yields, generating partially defatted meal as a byproduct, which can be subjected to further processing to increase the yield of oil extraction. Thus, studies about different methods of extraction and evaluation of the defatted material properties, such as color, water and oil holding capacity and solubility of the protein fraction were considered in this work.Key findings and conclusionsIt was found that the fatty acid composition of macadamia oil allows for its diverse use in many industries, i.e. cosmetics and pharmaceutical, while evaluation of the functional properties of the protein fraction of the defatted meal have shown that this byproduct can be used in food industry. Subsequent studies of the macadamia oil extraction process should enable the preservation of oil quality, in terms of fatty acid composition and bioactive compounds, and the functional properties of the defatted meal.     

Characterisation of odour‐active compounds in lupin flour

BACKGROUND: Lupin ingredients are promising alternatives to soybean products owing to their similarly high protein content. Lupin flour exhibits a green and bean‐like off‐flavour in higher amounts. The aim of this study was to characterise and identify the main odour‐active compounds in lupin flour. RESULTS: The orthonasal aroma of lupin flour was evaluated by means of aroma profile analysis and was found to be characterised by grassy‐green, metallic, fatty, fruity, hay‐like, cheese‐like, and meat‐like odour qualities. Volatile compounds of lupin flour of Lupinus angustifolius cv. Boregine were extracted with dichloromethane and isolated by solvent‐assisted flavour evaporation. Aroma extract dilution analysis (AEDA) was carried out with the obtained extract. In total, 50 odorants were detected by high‐resolution gas chromatography–olfactometry. AEDA revealed 26 odour‐active compounds with flavour dilution factors higher or equal to 32. The substances were unequivocally identified by their odour characteristics, their retention indices and their mass spectra using one‐dimensional or two‐dimensional gas chromatography–mass spectrometry, respectively. CONCLUSION: A series of unsaturated and saturated aldehydes, ketones, carboxylic acids, alkyl‐methoxypyrazines and terpenes were identified for the first time as odour‐active contributors to the aroma of lupin flour. Copyright © 2009 Society of Chemical Industry     

Some observations on wheat gluten solubilities

A study of wheat protein solubilities in dilute acetic acid is presented. Up to 4% more protein can be extracted from defatted flours than from the non-defatted flour. High-speed homogenisation can render up to 88% of flour protein and up to 97% of dough protein soluble. One criterion for optimum fatty acid or lipid protein interaction (causing protein insolubility) is that the fatty acids or lipids should contain C7-C9 hydrocarbon chain lengths.     

Compositional characteristics,texture, shelf-life and sensory quality of snack crackers produced from non-traditional ingredients

The study was conducted to evaluate the effect of non-traditional and highly available and nutrient-dense ingredients in the production of value-added crackers. The crackers were prepared by combining partially defatted chia flour, wheat germ, quinoa, and oat. The antioxidant activity and the polyphenol content were 7.0–8.4 times higher in crackers produced with non-traditional ingredients compared to the control snack. The hydroperoxide value indicated a low oxidative deterioration of the oil. The sample with 10% of partially defatted chia flour was selected for shelf-life test under storage conditions and sensory evaluation. Modified atmosphere exerted a protective effect on the lipid stability regardless of the incorporation of BHT to the formulation. All the evaluated attributes scored highly during consumer acceptance. The formulated cracker presented a relevant content of protein, dietary fibre and omega-3 and -6 fatty acids. Based on these results, the crackers containing non-traditional ingredients resulted in a product with a good potential for both consumer acceptance and outstanding nutritional benefits.     

新昌小京生花生的营养品质分析

目的:对浙江省新昌地区产花生品种小京生的基本理化性质、主要营养素含量、脂肪酸组成进行了研究。方法:采用直接干燥法测定水分含量,采用凯氏定氮法测定蛋白质含量,采用索氏测定粗脂肪含量,提取的油脂经甲酯化后用GS-MS分析脂肪酸组成。结果:小京生水分含量为4.98%、蛋白质含量24.48%、粗脂肪含量47.65%。油脂的主要由不饱和脂肪酸组成,占总脂肪酸的80.72%,其中油酸占54.88%,饱和脂肪酸占18.39%,油酸/亚油酸(O/L)比值为2.20。结论:小京生比普通花生含有更多蛋白质和不饱和脂肪酸,是营养价值优良的花生品种。     

Production of guava seed protein isolates: Yield,composition and protein quality

The optimum conditions were determined for the preparation of protein isolates from ground, defatted guava seed flour. The isolates were obtained by micellisation and isoelectric precipitation techniques. The isoelectric point of guava seed protein was found to be pH 4.5 with a protein solubility of more than 85% above pH 9. Using 40–80 mesh particle size and extracting at pH 10 for 30 min, an isoelectric isolate was obtained by acidification to pH 4.5 which was 85.4% of the starting protein compared to 18.3% for micellisation protein obtained by twofold dilution with cold distilled water of 5% NaCl protein extract. The isolates were easily digested by the pepsin-pancreatin enzyme system and were comparable to casein. The amino acid composition showed that guava seed flour and isolates were deficient in sulphur-containing amino acids and in lysine, but contained the other essential amino acids in adequate levels. The micellisation isolate had higher fat absorption and emulsion stability than the isoelectric isolate, while other functional properties were almost similar.     

Antiradical and antimicrobial properties of cold-pressed black cumin and cumin oils

Cold-pressed black cumin seed oil (BCSO) and cumin seed oil (CSO) were evaluated for their fatty acid profiles, phytosterol and tocopherol contents, antiradical properties and inhibition of microbial growth. The main fatty acids in BCSO were linoleic followed by oleic and palmitic acids. Petroselinic acid (C18:1n-12) was the main fatty acid in CSO, while linoleic acid was the second major unsaturated acid. Six sterol compounds were measured in BCSO and CSO, wherein the sterol marker was β-sitosterol. α-Tocopherol constituted 45% of tocopherols in BCSO, while β-tocopherol was the main component in CSO. BCSO and CSO oils had higher antiradical action against DPPH· and galvinoxyl radicals than virgin olive oil. Antimicrobial properties of BCSO and CSO were studied, and the results revealed that CSO inhibited the growth of all microorganisms tested, while BCSO inhibited the growth of all microorganisms tested except A. niger and A. flavus. BCSO and CSO had a drastic effect on the biosynthesis of protein and lipids in cells of B. subtilis.     

Comparison of soybean oils, gum, and defatted soy flour extract in stabilizing menhaden oil during heating

ABSTRACT:  Capabilities of crude soy oil, degummed oil, gum, and defatted soy flour extract in preventing the oxidation of menhaden oil and its omega-3 fatty acids, DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid), during heating were evaluated. The menhaden oil mixed with defatted soy flour extract demonstrated the greatest stability by producing the lowest TBA reactive oxidation products and retaining the highest concentrations of DHA and EPA after heating at 150 °C for 30 min. A range of 62.8% to 71.5% of DHA and 67.7% to 75.9% of EPA remained in the fish oil with defatted soy flour extract, while only 29.9% of DHA and 37.2% of EPA were retained in the fish oil with no addition. Stabilizing capability from highest to lowest was defatted flour extract > gum > degummed oil = crude oil. The defatted flour extract had the highest level of total phenolic content (11.3 μg catechin equivalent/g), while crude oil, degummed oil, and gum contained 7.1, 6.1, and 6.0 μg catechin equivalent/g, respectively. The level of isoflavones in the defatted soy flour extract was 55 mg/g, which was over 100 times higher than in the crude oil or gum. Although isoflavones were not detected in the degummed oil, it contained the highest level of tocopherols (414 μg/g), whereas the lowest level (215 μg/g) was found in the defatted flour extract. The order of free radical scavenging capability measured from high to low was the defatted soy flour extract, crude oil, degummed oil, and gum.     

Quality characteristics of wheat flour milled streams

In order to develop specific quality flour for use in different bakery products, quality characteristics such as sedimentation value, flour color and oil and its fatty acid composition of flour mill streams obtained from three different commercial roller flour mills were determined. The studies showed there was an increase in the sedimentation value, protein, falling number and oil and a decrease in flour color with increasing number of break flour streams, and the trend was similar for the streams obtained from the three different mills. However, no appreciable difference with regard to the above parameters was observed in reduction flour streams. Palmitic and linoleic acid contents were the predominant saturated and unsaturated fatty acids respectively present in oil of the milled streams. The levels of these fatty acids were high in V break, 1st, 2nd, 3rd and 6th reduction streams in all three mills. The flours from the reduction passages in general had more saturated fatty acid compared to break flour streams.     

Death rate of Salmonella oranienburg in fish meals as influenced by autoxidation treatment

Fish meals and fish flour with low oil content were artificially infected with Salmonella oranienburg. In nine trials the effect of moisture content, temperature, atmospheric oxygen content, addition of an antioxidant, ethoxyquin (EQ) and of some short chain unsaturated organic acids, crude fish oil, a highly unsaturated fraction of fish oil, the free fatty acids derived from this fraction and of different extracts of fish meals on the death rate of Salmonella, was studied. Elevated temperature (30 ºC), an oxygen atmosphere and material containing highly unsaturated oils or fatty acids accelerated Salmonella death rate. EQ was shown not to have a bactericidal action and when added in conjunction with highly unsaturated oil or fatty acids counteracted the bactericidal effect of these materials. A high death rate seemed to accompany active oxidation in the test media.     

SOME ASPECTS OF THE STRUCTURE AND FUNCTION OF THE YEAST PLASMA MEMBRANE

The permeation of many compounds into the yeast cell is largely regulated by the plasma membrane according to their lipid solubility and degree of dissociation. Thus the permeation rate of the fatty acids and α-keto acids is proportional to their relative lipid solubility. The highly dissociated and poorly lipid-soluble di- and tri-carboxylic acids and halogenated acetic acids permeate only very slowly; the impermeable α-ketoglutaric acid becomes easily permeable when made lipid-soluble by esterification. The lipid composition of the plasma membrane can thus be of decisive importance in regulating the movement of different compounds into and out of the yeast cell. Lipid analyses revealed that anaerobiosis clearly affected the neutral lipid composition of the plasma membrane. The aerobic membrane contained more unsaturated fatty acids, mainly palmitoleic and oleic acids, more total sterol, much more ergosterol and much less squalene. The principal sterol in the aerobic membrane, ergosterol, was mainly in the free form, whereas zymosterol and other minor sterols were predominantly esterified. In contrast, the anaerobic membrane contained small amounts of biosynthetic sterol precursors of ergosterol, and was clearly richer in saturated fatty acids having a greater variation in chain length. Both plasma membranes contained a considerable amount of triacylglycerols.