Influence of Argan Kernel Roasting-time on Virgin Argan Oil Composition and Oxidative Stability

Virgin argan oil, which is harvested from argan fruit kernels, constitutes an alimentary source of substances of nutraceutical value. Chemical composition and oxidative stability of argan oil prepared from argan kernels roasted for different times were evaluated and compared with those of beauty argan oil that is prepared from unroasted kernels. Prolonged roasting time induced colour development and increased phosphorous content whereas fatty acid composition and tocopherol levels did not change. Oxidative stability data indicate that kernel roasting for 15 to 30 min at 110 °C is optimum to preserve virgin argan oil nutritive properties.     

Nutritional quality of pearl millet flour and bread

Market samples of pearl millet flour and bread from Saudi Arabia were analysed for chemical composition and nutritional quality. Pearl millet flour contained, on a dry weight basis, 17.4% protein, 6.3% fat, 2.8% fiber and 2.2% ash. Lysine was the most limiting essential amino acid with a chemical score of 53 (FAO/WHO, 1973). Linoleic acid (44.8%), oleic acid (23.2%) and palmitic acid (22.3%) were the dominant fatty acids in millet oil followed by stearic acid (4.0%) and linolenic acid (2.9%). The invitro protein digestibility (IVPD) of millet flour was 75.6% and the calculated protein efficiency ratio (C-PER) was 1.38 in comparison to ANRC casein values of 90% and 2.50, respectively. Baking at 300°C for 15 min had only little effect on the proximate and fatty acid composition of the bread but decreased the arginine, cystine and lysine contents by 31.3%, 15.8% and 13.8%, respectively. The IVPD was not affected but the C-PER decreased by 18% on baking.     

Protein quality evaluation of sprouted maize

Protein, lysine, tryptophan, crude fibre (CF) and neutral detergent fibre (NDF) of sprouted, normal and hard endosperm opaque-2 (QPM) kernels increased, whereas in vitro protein digestibility (IVPD) decreased substantially up to five days of germination. Following the removal of radicles alone or both radicles and plumules from sprouted kernels, IVPD improved at all the stages of germination. However, the contents of lysine and tryptophan were not affected significantly. For some stages of germination, these amino acids decreased slightly. In sprouted normal kernels, IVPD was higher whereas protein, lysine and tryptophan content was lower than that of sprouted QPM kernels respectively at all the stages of germination. In four days old sprouted normal kernels, after the removal of both radicles and plumules biological value (BV), net protein utilization (NPU) and utilizable protein (UP) increased over non-sprouted kernels whereas true digestibility (TD) reach at par with non-sprouted kernels.     

Effects of heat on the removal of polyphenols and in vitro protein digestibility of cowpea (Vigna unguiculata (L.) Walp.)

Simple wet heat treatments like simple boiling (atmospheric pressure, 100 °C) and pressurized boiling (higher than 100 °C) reduced the polyphenol content of mature dark red seeds of cowpea (Vigna unguiculata (L.) Walp.) cultivar UPL Cp 3 by 61 to 80% and improved in vitro protein digestibility (IVPD) by 6 to 26%. Pressurized steaming (higher than 100 °C) removed 48 to 83% of the polyphenols but increased IVPD by only 1.1 to 4.2%. Dry heat as exemplified by roasting and microwave treatment inactivated 58 to 71% of the tannins but increased IVPD by only 1%. All the heat treatments were effective in removing/inactivating polyphenols though different responses were observed with the resulting in vitro protein digestibilities.     

Comparative study on the effects of buckwheat by roasting: Antioxidant properties,nutrients, pasting,and thermal properties

The increasing need to prolong the shelf life of buckwheat has prompted the use of roasting techniques in buckwheat processing. For effective roasting, the responses of common buckwheat (CB) and tartary buckwheat (TB) to the process should be explored. Herein, the antioxidant properties, nutrients, pasting, and thermal properties of raw and roasted buckwheat flours (roasted at 200 °C for 50 s) from two CB and three TB varieties were investigated. Results showed that roasting considerably reduced the total flavonoid content (TFC) and total phenolic content (TPC) of TB. The TPC of CB was significantly improved by roasting, whereas the TFC significantly decreased. The total antioxidant capacities were consistent with the TPCs. Additionally, the colour deepened as the amount of antioxidant compounds increased. Unexpectedly, roasting enhanced the protein and fat contents of CB and decreased those of TB. Roasting improved the nutritional quality and antioxidant capacity of CB, and opposite results were obtained in TB. In conclusion, CB was more suitable to the development of roasted specialty products with nutritional applications than TB. We suggest that differences among varieties should be considered first in the buckwheat roasting process.     

Relevance of fermented food products in southwest Nigeria

Samples of extruded high protein weaning foods were produced using blends of peanuts, maize and soybean to achieve the desired level of protein. The extruded products, based on a raw and a preroasteds mix of ingredients, were developed and characterized in terms of the hot paste viscosity characteristics, chemical and nutritional quality, amino acid composition, and storage stability. A comparative evaluation of the extruded products was undertaken in relation to two similar existing products: the traditional roasted maize flour weaning food, and thecommercial version. In general, the extruded products were found to have better nutritional quality as indicated by the high protein content of 16.5–18.7% and quality, and excellent rat growth response. For both types of extruded weaning foods developed, between sixty- and one hundred-fold increases in mean weight gain of test rats were recorded over those eating the traditional sample. Correspondingly, the PER values which were between 2.3 and 2.5, were almost thrice the values obtained for the existing products. Significantly higher feed efficiency ratios were also obtained for the extruded products. Hematological data of test animals showed normal values for white blood cell (WBC) count, red blood cell (RBC) count, hemoglobin (Hb) levels and packed cell volume (PCV) for all the weaning foods studied, except the existing traditional roasted maize flour. In terms of storage stability of the extruded products, predicted shelf life periods of 7.8–10.4 months were obtained for the extruded raw blend, and 5.6–7.1 months for the extruded preroasted blend when stored at the average ambient temperature of about 30,°C in Ghana. In general, the preroasting treatment was found to reduce the quality characteristics of the extruded product.     

Erratum to: Antioxidant Properties of Extracts Obtained from Raw, Dry-roasted, and Oil-roasted US Peanuts of Commercial Importance

Raw, skinless peanut kernels from US commercial production lines were dry- and oil-roasted according to standard industrial practices. Eighty percent (v/v) methanolic extracts from the peanut cultivars were prepared and characterized by RP-HPLC: five predominant compounds were found comprising free p-coumaric acid and potential p-coumaric acid derivatives, as elucidated by DAD-UV spectra with comparisons to those of commercial standards. A Spanish high-oleic peanut possessed the greatest naturally-occurring level of p-coumaric acid and its derivatives, followed by a high-oleic Runner, a normal Runner, and a Virginia peanut. Upon thermal processing, p-coumaric acid was liberated at the expense of its derivatives according to the relationship: oil roasting > dry roasting > raw. A high-oleic Runner exhibited the greatest increase (∼785%) in free p-coumaric acid levels after oil roasting. For many of the samples from the 2007 crop, processing increased the TPC and antioxidant capacities in the order of raw < dry roast < oil roast, but results were cultivar dependent. Oil-roasted peanuts were more effective at scavenging O₂ ^●- than their dry-roasted counterparts, as determined by a photochemiluminescence assay. Overall findings indicate that although thermal processing altered the composition of peanut kernel antioxidants, TPC values and radical-scavenging activities are preserved. Depending on peanut type, cultivar, and harvest date, enhanced antioxidant capacities can result.     

Protein quality of chickpea (Cicer arietenum) with different grades ofCallosobruchus chinensis L. infestation

Dry heat treatments at 140 °C for 20 min or 160 °C for 10 min of peanut kernels significantly improved protein solubility, water and oil absorptions, foaming capacity and stability, and least gelation concentration of the defatted meal. However, heat treatments at 160 °C for 30 min or more than 30 min period resulted in significant decrease in these properties. Such heat treatments significantly decreased the level of albumin and globulin fraction with concomitant increase in glutelin fraction in the meal.     

Physical,morphological and chemical characteristics,oil recovery and fatty acid composition of Balanites aegyptiaca Del. kernels

Balanites aegyptiaca Del. kernels were chemically,physically and morphologically characterized. Crude oil (49.0%) andcrude protein (32.4%) were the two major constituents of the kernels.Phytic acid content was relatively high compared to other legumes. Incontrast, antitryptic activities of the kernel flours were very low.Sapogenin contents of the full fat, defatted and testa flours were 1.5, 2.7and 3.0%, respectively. The hardness of the kernel was found to be about10.4 × 10⁵ N/m², which was somewhat high. The morphologicalstructure of the kernel using a scanning electron microscope revealedthat the protein matrix was embedded in a lake of oil droplets. Oilrecovery, as a function of pressing time, pressure, temperature and particlesize was investigated. With increasing temperature up to 70 ^°C at 400 bar, for 120 min, an oil recovery of 79.4% wasobtained. Using an expeller at 115 ^°C, about 85% of thekernel oil was recovered. The reduction of particle size had a negativeeffect on oil recovery under the same conditions. The fatty acidcomposition was not affected by the pressing temperature up to 115 ^°C. The total amount of the unsaturated fatty acids was found tobe up to 74.8% (50 ^°C) and 75.1% (115 ^°C)of the total fatty acids content.     

Antioxidant Properties of Extracts Obtained from Raw,Dry-roasted,and Oil-roasted US Peanuts of Commercial Importance

Raw, skinless peanut kernels from US commercial production lines were dry- and oil-roasted according to standard industrial practices. Eighty percent (v/v) methanolic extracts from the peanut cultivars were prepared and characterized by RP-HPLC: five predominant compounds were found comprising free p-coumaric acid and potential p-coumaric acid derivatives, as elucidated by DAD-UV spectra with comparisons to those of commercial standards. A Spanish high-oleic peanut possessed the greatest naturally-occurring level of p-coumaric acid and its derivatives, followed by a high-oleic Runner, a normal Runner, and a Virginia peanut. Upon thermal processing, p-coumaric acid was liberated at the expense of its derivatives according to the relationship: oil roasting > dry roasting > raw. A high-oleic Runner exhibited the greatest increase (～785%) in free p-coumaric acid levels after oil roasting. For many of the samples from the 2007 crop, processing increased the TPC and antioxidant capacities in the order of raw < dry roast < oil roast, but results were cultivar dependent. Oil-roasted peanuts were more effective at scavenging O₂ ^●- than their dry-roasted counterparts, as determined by a photochemiluminescence assay. Overall findings indicate that although thermal processing altered the composition of peanut kernel antioxidants, TPC values and radical-scavenging activities are preserved. Depending on peanut type, cultivar, and harvest date, enhanced antioxidant capacities can result.     

In vitro Gastrointestinal Digestion of Glabrous Canaryseed Proteins as Affected by Variety and Thermal Treatment

Glabrous or hairless canaryseed is a nutritional grain that could be a good addition to the diet if approved as a novel food. To assess the impact of thermal treatment on its digestibility; raw, roasted or boiled flours prepared from three different varieties of glabrous canaryseed were subjected to in vitro gastrointestinal digestion conditions and the effect on protein electrophoretic profiles was examined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Roasting was done by dry-heat in an oven at 176 °C for 12 min whereas boiling was done in water at 98 °C for 12 min. SDS-PAGE showed approximately twenty-five protein bands in the undigested raw flour with molecular masses (MM) ranging from <14 kDa to >97 kDa. The dominant proteins had low MM, between the ranges of ~57 to 12 kDa. Roasting markedly altered the protein electrophoretic profile with the appearance of large molecular weight aggregates. Canaryseed proteins were more easily digested after thermal treatment and under sequential gastric-duodenal conditions than under gastric or duodenal conditions alone. Furthermore, roasting appeared to have a greater impact on in vitro protein digestibility than boiling.     

Composition and oxidative stability of crude oil extracts of corn germ and distillers grains

The fatty acid composition, Acid Value, and the content and composition of tocopherols, tocotrienols, carotenoids, phytosterols, and steryl ferulates were determined in corn germ oil and four post-fermentation corn oils from the ethanol dry grind process. The oxidative stability index at 110 °C was determined for the five oils, and four oils were compared for their stability during storage at 40 °C as determined by peroxide value and hexanal content. The fatty acid composition of all five oils was typical for corn oil. The Acid Value (and percentage of free fatty acids) was highest (28.3 mg KOH/g oil) in corn oil extracted centrifugally from a conventional dry grind ethanol processing facility and for oil extracted, using hexane, from distillers dried grains with solubles (DDGS) from a raw starch ethanol processing facility (20.8 mg KOH/g oil). Acid Value was lowest in two oils extracted centrifugally from thin stillage in a raw starch ethanol facility (5.7 and 6.9 mg KOH/g oil). Tocopherols were highest in corn germ oil (∼1400 μg/g), but tocotrienols, phytosterols, steryl ferulates, and carotenoids were higher in all of the post-fermentation corn oils. Hexane extracted oil from DDGS was the most oxidatively stable as evaluated by OSI and storage test at 40 °C, followed by centrifugally extracted thin stillage oil from the raw starch ethanol process, and centrifugally extracted thin stillage oil from the conventional dry grind ethanol process. Corn germ oil was the least oxidatively stable. When stored at room temperature, the peroxide value of centrifugally extracted thin stillage oil from the raw starch ethanol process did not significantly increase until after six weeks of storage, and was less than 2.0 mequiv. peroxide/kg oil after three months of storage. These results indicate that post-fermentation corn oils have higher content of valuable functional lipids than corn germ oil. Some of these functional lipids have antioxidant activity which increases the oxidative stability of the post-fermentation oils.     

Phytic acid,in vitro protein digestibility,dietary fiber,and minerals of pulses as influenced by processing methods

The objective of this project was to determine the effect of various types of processing on selected nutrition related parameters of commonly consumed Indian pulses and soybean. Germination reduced the phytic acid content of chickpea and pigeonpea seeds by over 60%, and that of mung bean, urd bean, and soybean by about 40%. Fermentation reduced phytic acid contents by 26–39% in all these legumes with the exception of pigeonpea in which it was reduced by more than 50%. Autoclaving and roasting were more effective in reducing phytic acid in chickpea and pigeonpea than in urd bean, mung bean, and soybean. Germination and fermentation greatly increased the in vitro protein digestibility (IVPD). IVPD was only slightly increased by roasting and autoclaving of all legumes. Germination and fermentation also remarkably decreased the total dietary fiber (TDF) in all legumes. Autoclaving and roasting resulted in slight increases in TDF values. All the processing treatments had little effect on calcium, magnesium and iron contents.     

TO-891制茶专用油脂的研究

采取食用级茶籽油经氢化和脂肪酸重组处理研制而成的 TO-891制茶专用油脂,外观为乳白色固体,无杂质,无异味,熔点50—58℃;酸价≤4;过氧化值(出厂)<0.15%;饱和脂肪酸含量70%以上(其中中碳酸含量50%以上)。该产品的热稳定性能好,抗酸败能力强,便于运输,耐贮藏。与传统的柏油相比,它具有使用方便、清洁卫生和用量少等优点。1989—1990年在浙江、安徽、江苏、江西、湖北、湖南及福建等省30多个产茶县在炒制龙井、旗枪、大方、珠茶、炒青及各种名茶中试用推广,结果表明,该油脂完全适合炒制绿茶的工艺要求,并能改善茶叶品质,经济效益显著。它的研制成功,为我国制茶用油的科学化、标准化和规范化提供了条件。     

Protein Nutritional Quality of Infant Cereals during Processing

The most common food for weaning at the age of 4–6 months is cereal since is that it is a good source of high quality protein. However, processing may affect this quality. The aim of the present study was ascertain the changes that take place during four processing stages of infant cereals (in the raw materials, after roasting, after enzymatic treatment and drum drying, and in the commercial product), the following protein nutritional parameters: crude and true protein (CP and TP, respectively), in vitro protein digestibility (IVPD), free amino acids (FAA), calculated protein efficiency ratio (C-PER) and total amino acids profile. Of the infant cereals studied two contained gluten (‘Multicereal’ and ‘Wheat’) and two were gluten-free (‘Growth’ and ‘Rice and carrot’). All the parameters studied were affected by the different processing stages, but none showed a clear trend. The CP and TP content decreased after heat treatment (roasting) with a consequent increase in FAA content due to protein hydrolysis and the release of amino acids. IVPD remained stable during the processing stages in all the infant cereals, except in ‘Wheat’, while C-PER increased significantly. Infant cereals containing gluten showed higher CP and TP contents, and also higher IVPD than gluten free cereals, in which a digestibility value higher than 75% was reached. The overall content of essential amino acids, including sulphur amino acids, was acceptable (equal to or higher than FAO/WHO recommendations), although lysine (Lys) was the limiting amino acid in all the infant cereals.     

Nutritional studies on rats and fish (carp Cyprinus carpio) fed diets containing unheated and heated Jatropha curcas meal of a non-toxic provenance

Unheated and heated (121 ^°C, 66% moisture; 15, 30 and 45 min) Jatropha meals of non-toxic provenance from Veracruz state in Mexico were evaluated using rats and fish. With rats, the weight gain was highest for the casein diet followed by heated (30 min; only this treatment was studied using rats) and unheated Jatropha meal containing diets. The protein efficiency ratio (PER) for unheated and heated Jatropha meal containing diets was 37 and 86%, respectively, of the casein diet. On the other hand, the body weight gain, PER and feed conversion ratio of fish were statistically similar for unheated and heated (15, 30 and 45 min) Jatropha meal containing diets fed for a period of 35 days. Although these parameters were statistically similar for the unheated and heated Jatropha meal containing diets, the body weight gain, PER and protein productive value were highest and the feed conversion ratio lowest with 15 min heated Jatropha meal, suggesting that the heat treatment for 15 min is optimal for the meal. Trypsin inhibitor and lectin activities decreased drastically (>83 and 99%, respectively) after 30 and 45 min of heat treatment and after 15 min, the residual lectin activity was negligible and the residual trypsin inhibitor activity was 34%. These results, together with the nutritional parameters investigated, imply that Jatropha trypsin inhibitors and lectins do not have any adverse effects on carp at least up to 35 days of feeding. The nutritional value of Jatropha meal of the non-toxic provenance is high, and potential exists for its incorporation into the diets of monogastrics, fish and possibly humans.     

Characteristics, composition and thermal stability of Acacia senegal (L.) Willd. seed oil

The chemical composition, main physicochemical properties and thermal stability of oil extracted from Acacia senegal seeds were evaluated. The oil, moisture and the ash contents of the seeds were 9.80%, 6.92% and 3.82%, respectively. Physicochemical properties of the oil were iodine value, 106.56 g/100 g of oil; saponification value, 190.23 mg KOH/g of oil; refractive index (25 °C), 1.471; unsaponifiable matter, 0.93%; acidity, 6.41% and peroxide value, 5.43 meq. O₂/kg of oil. The main fatty acids in the oil were oleic acid (43.62%) followed by linoleic acid (30.66%) and palmitic acid (11.04%). The triacylglycerols (TAGs) with equivalent carbon number ECN 44 (34.90%) were dominant, followed by TAGs ECN 46 (28.19%), TAGs ECN 42 (16.48%) and TAGs ECN 48 (11.23%). The thermal stability analysed in a normal oxidizing atmosphere showed that the oil decomposition began at 268.6 °C and ended at 618.5 °C, with two stages of decomposition at 401.5 °C and 576.3 °C. According to these results, A. senegal seed oil has physicochemical properties, fatty acids composition and thermal characteristics that may become interesting for specific applications in several segments of food and non-food industries.     

Changes in oil,sugars and nitrogenous components during germination of sunflower seeds,Helianthus annuus

Since germination has been found to improve the nutritional quality of grains, sunflower seeds Helianthus annuus were germinated for up to five days, and the cotyledons were analyzed for oil, sugar, free amino acid, non-protein nitrogen, lysine, tryptophan and methionine contents. Protein was fractionated. Soaking and germination increased the non-protein nitrogen, total free amino acid, lysine and tryptophan contents. Protein content and dry weight decreased. The oil content decreased significantly after 72 hours of germination. The reducing sugars increased gradually until day five of germination.The saline soluble albumin and globulin fractions decreased while the glutelin content increased during germination. No changes were noticed in the prolamin and methionine contents.     

Supercritical carbon dioxide (SC-CO2) extraction of Nigella sativa L. oil using full factorial design

In this study, Nigella sativa L. oil was extracted using supercritical carbon dioxide with full factorial design to determine the best extraction condition (pressure, temperature and dynamic extraction time) for obtaining an extract with high yield, antioxidant activity and thymoquinone (TQ) quantity. The maximum thymoquinone content in the highest overall yield was achieved through SC-CO₂ extraction condition of 150 bar, 40 °C, 120 min with the value of 4.09 mg/ml. The highest SC-CO₂ extraction yield was 23.20% which obtained through extraction condition of 350 bar, 60 °C and 120 min. The extraction conducted at 350 bar, 50 °C, 60 min showed the lowest IC₅₀ value (highest antioxidant activity) of 2.59 mg/ml using DPPH radical scavenging activity method. Fatty acid composition of the extracted oil with highest radical scavenging activity was obtained by gas chromatographic analysis.     

Effects of roasting on barley β-glucan,thermal, textural and pasting properties

Different hulled barley cultivars were subjected to roasting in hot sand (280 °C) and the effects on β-glucan extractability, physico-chemical, thermal and pasting properties were studied. The grain puffed upon roasting and grain hardness and colour difference ΔE were significantly lowered. The roasted barley flour had significantly higher water absorption and water solubility index. The cultivars DWR-28, RD-2503 and PL-172 had the highest total β-glucan content (up to 5.47%). Roasting brought about a decrease in the soluble β-glucan content in all the cultivars and this decrease ranged from 4.9 to 25.3%. The β-glucan extractability was not affected by the roasting process but roasting lowered the ratio of soluble to insoluble β-glucan content by 8.1–41.9%. Roasting significantly affected the pasting and thermal properties of the flours, together with an increase in the cooked starch content that ranged from 28.8 to 43.1%.