Chlorogenic Acid Oxidation and Its Reaction with Sunflower Proteins to Form Green‐Colored Complexes

Sunflower seeds are used to produce oil for human consumption, but its protein meal by‐product has long been used as animal feed. Formation of green‐colored complexes through oxidized chlorogenic acid(CGA)‐protein interactions is a primary reason why defatted sunflower protein has not been widely utilized by the food industry. Sunflower protein possesses many properties that make it an appealing alternative protein source from both a marketing and formulation perspective, including its low cost, absence of major allergens, low antitrypsin inhibitors, and its status as both vegan and “clean” label friendly. With the global demand for sunflower oil and novel protein sources expected to increase and waste recovery a concern for many, providing uses for the sunflower meal and its fiber and polyphenol components would provide added value to by‐products from sunflower oil processing. This review addresses the unique green pigmentation associated with the interaction of sunflower protein and oxidized CGA by outlining the sunflower oil and protein meal market, CGA reactions contributing to greening, methods for CGA extraction, and the effect of processing on sunflower protein quality and the greening reaction. This review also addresses potential food applications of sunflower protein‐based ingredients, such as addition of texturized protein to food products; a microencapsulation matrix for antioxidants; edible, flexible biodegradable films; and even use of sunflower butter as an alternative to peanut butter where the green color is not considered undesirable. Continued studies are needed to make sunflower‐based products and CGA‐extraction processes available across the global marketplace.     

Decrease of the chlorogenic acid content in commercial sunflower meal using a polyphenol oxidase preparation secreted by the white‐rot fungus Trametes versicolor ATCC 42530

BACKGROUND: Sunflower meal (SFM) is a by‐product from the oil extraction process from sunflower seeds. The meal is used as a protein supplement in the livestock diet. However, relatively high levels of polyphenols, among which chlorogenic (CGA) and caffeic acids are in larger amounts, in the meal compromises its use for animal feed and human consumption. The aim of this work was to investigate an enzymatic process for upgrading the quality of SFM by decreasing its CGA content using an enzyme preparation from the white‐rot fungus Trametes versicolor. RESULTS: The effects of pH, temperature, enzyme and meal concentrations, and mass transfer on the decrease of the CGA content in SFM were investigated. It was found that: (1) the optimum pH and temperature were 3.4 and 45 °C, respectively. (2) The system was saturated with the enzyme when its concentration was 5 nkat/mL of liquid phase; (3) the agitation speed of the system influenced the extraction of CGA from the meal; and (4) the conversion of CGA in the SFM system increased in the presence of larger volumes of liquid phase. CONCLUSIONS: The enzyme preparation used in the experiments is able to decrease successfully the CGA content in SFM. Copyright © 2007 Society of Chemical Industry     

Antioxidant activity of ginger extract in sunflower oil

The antioxidant activity of dichloromethane extract from ginger was evaluated during 6 months of storage of refined sunflower oil at 25 and 45 °C. Free fatty acid (FFA) content, peroxide value (POV) and iodine value (IV) were used as criteria to assess ginger extract as an antioxidant. After 6 months of storage at 45 °C, sunflower oil containing 1600 and 2400 ppm ginger extract showed lower FFA contents (0.083 and 0.080%) and POVs (24.5 and 24.0 meq kg^?1) than the control sample (FFA contents 0.380%, POV 198.0 meq kg^?1). Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) showed FFA contents of 0.089 and 0.072% and POVs of 26.5 and 24.7 meq kg^?1 respectively after 6 months of storage at 45 °C. Similarly, after 6 months of storage at 45 °C, IVs of sunflower oil containing 1600 and 2400 ppm ginger extract were 80 and 92 respectively, higher than that of the control sample (53). However, IVs of sunflower oil treated with 200 ppm BHA and BHT were 94 and 96 respectively after 6 months of storage at 45 °C. These results illustrate that ginger extract at various concentrations exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT). Ginger extract also showed good thermal stability and exhibited 85.2% inhibition of peroxidation of linoleic acid when heated at 185 °C for 120 min. Therefore the use of ginger extract in foods is recommended as a natural antioxidant to suppress lipid oxidation. © 2003 Society of Chemical Industry     

焙炒处理对不同植物油品质特性的影响北大核心CSCD

为了研究焙炒对植物油品质的影响,以油菜籽、亚麻籽、花生、葵花籽和芝麻为原料,经焙炒处理后采用液压压榨法制油(热榨油),分析植物油的理化指标(酸值、过氧化值、水分及挥发物、色泽)、主体组分(脂肪酸组成及含量、甘三酯组成及含量、挥发性组分)和总酚含量,并与未焙炒处理直接压榨制取的油(冷榨油)作对比。结果表明:热榨油酸值和过氧化值显著高于冷榨油(p<0.05),其中,热榨亚麻籽油酸值(KOH)最高(0.96 mg/g),热榨菜籽油过氧化值最高(1.02 mmol/kg);冷榨油水分及挥发物含量显著高于热榨油(p<0.05),其中冷榨花生油水分及挥发物含量最高(0.16%);热榨油的色泽较冷榨油深,其中热榨菜籽油的色泽最深(R1.1,Y31);焙炒对植物油脂肪酸和甘三酯组成及含量无显著影响(p>0.05);热榨油中醇类、醛类和酸类等挥发性组分较少,但杂环类物质较多;热榨菜籽油、亚麻籽油、花生油、葵花籽油和芝麻油总酚含量分别是其冷榨油的1.38、1.57、1.51、1.80倍和1.27倍。因此,焙炒对植物油品质影响较大,应根据生产需要选择合适的预处理方式。     

Use crude olive leaf juice as a natural antioxidant for the stability of sunflower oil during heating

Olive leaves (Kronakii cultivar) were obtained from the annual pruning of olive trees and pressed to obtain a crude juice. Aliquots from the concentrated crude olive leaf juice, representing 400, 800, 1600 and 2400 ppm as polyphenols, were added to sunflower oil. Samples of sunflower oil mixed with olive leaf juice were heated intermittently at 180 ± 5 °C for 5 h day^?1 and the heating process was repeated for five consecutive days. A control experiment was performed where butylated hydroxyl toluene (BHT) at 200 ppm was added to sunflower oil prior to intermittent heating in order to compare the antioxidant efficiency between the natural polyphenolics of olive leaf juice and synthetic antioxidant BHT. Some physical and chemical constants for the unheated and heated sunflower oil were determined. The data indicate that the addition of olive leaf juice to sunflower oil heated at 180 °C induced remarkable antioxidant activity and at 800 ppm level was superior to that of BHT in increasing sunflower oil stability.     

Hypolipidemic effect of enzymatically extracted sunflower seed protein fraction

An attempt was made to enzymatically extract the protein fraction (PF) from sunflower seeds and investigate its dietary effect on the growth, plasma and tissue lipid profiles, plasma protein content, erythrocyte membrane lipid profile and organ weights of rats. Extraction of dehulled sunflower seeds in an aqueous medium in the presence of the enzyme pectinase at 50 ± 1 °C and pH 4.5 yielded a protein fraction with low residual chlorogenic acid and fibre contents. Rats fed the sunflower seed protein fraction showed a similar body weight gain and food efficiency ratio as rats fed casein. However, the different dietary proteins had different effects on plasma total cholesterol and triglyceride contents. The rats fed the sunflower seed protein fraction showed a significant decrease in plasma cholesterol (p < 0.02) and triglyceride (p < 0.02) concentrations compared to the casein‐fed rats. The PF‐fed rats also exhibited a significant difference in erythrocyte membrane phospholipids and phosphatidylcholine/phosphatidylethanolamine ratio. Rats fed the different dietary proteins did not show much variation in plasma protein content, liver and brain lipids and organ weights. These results demonstrate the hypolipidemic action of the sunflower seed protein fraction and that it can be considered a suitable edible protein like casein. © 2000 Society of Chemical Industry     

Compositional changes in seeds influenced by their positions in different whorls of mature sunflower head

The physicochemical characteristics of seeds located in different whorls of the sunflower (Helianthus annuus L) head at maturity have been studied. The proportion of filled seeds decreased from the peripheral to the central whorl, with a 10‐fold decrease in filled/unfilled seed ratio. The dry weight of seeds and kernels and the oil content of kernels decreased from the peripheral towards the middle and central whorls. However, the dry weight of seeds and kernels in the seed crop was significantly higher and the oil content lower than in the oil crop. The contents of starch, total soluble sugars and reducing sugars were lower in the oil crop than in the seed crop. The starch content of peripheral whorls in the seed crop was much lower than that of central whorls, with accumulation of total soluble sugars and reducing sugars, whereas much less variability was observed with respect to the position of seeds on the sunflower head in the oil crop. The mean proportion of membrane lipids was higher and that of triacylglycerols lower in the seed crop than in the oil crop. The proportions of 16:0 and 18:1 were higher in the seed crop, while that of 18:2 was higher in the oil crop. Copyright © 2003 Society of Chemical Industry     

Antioxidant Effect of Poleo and Oregano Essential Oil on Roasted Sunflower Seeds

The objective was to evaluate the stability of sensory and chemical parameters in roasted sunflower seeds supplemented with oregano and poleo essential oils; and the consumer acceptability of this product. Four samples were prepared: plain roasted sunflower seeds (Control = RS‐C), and sunflower seeds added with oregano (RS‐O) or poleo (RS‐P) essential oils or BHT (RS‐BHT). Consumer acceptance was determined on fresh samples. The overall acceptance averages were 6.13 for RS‐C, 5.62 for RS‐P, and 5.50 for RS‐O (9‐point hedonic scale). The addition of BHT showed greater protection against the oxidation process in the roasted sunflower seeds. Oregano essential oil exhibited a greater antioxidant effect during storage than poleo essential oil. Both essential oils (oregano and poleo) provided protection to the product, inhibiting the formation of undesirable flavors (oxidized and cardboard). The antioxidant activity that presents essential oils of oregano and poleo could be used to preserve roasted sunflower seeds.     

Antioxidant effects of rosemary extracts on sunflower oil compared with synthetic antioxidants

The antioxidant activities of ethanol extracts of rosemary (Rosmarinus officinalis L.) (RE) were tested in natural sunflower oil stored at 60 °C by measuring their peroxide values (POV), thiobarbituric acid‐reactive substances (TBARS), free fatty acid (FFA) content and p‐anisidine value (AnV) after regular intervals compared with synthetic antioxidants. After 3 weeks of storage at 60 °C, sunflower oil containing 200 mg kg^?1 rosemary extracts showed lower POVs (75.7 ± 0.47  meq kg^?1), thiobarbituric acid‐reactive substances (TBARS)(0.161 ± 0.002 μg mL^?1), FFA contents (0.45 ± 0.04 mg g^?1) and AnV (12.4 ± 0.02) than the control sample. Sunflower oil containing 200 ppm butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) showed POVs (204 ± 0.68, 159 ± 0.55, 20 ± 0.49 meq kg^?1), thiobarbituric acid‐reactive substances (TBARS) (0.171 ± 0.002, 0.184 ± 0.002, 0.069 ± 0.001 μg mL^?1), FFA contents (0.34 ± 0.03, 0.46 ± 0.03, 0.2 ± 0.01 mg g^?1) and AnV (14.7 ± 0.03, 16.5 ± 0.04, 6.77 ± 0.01), respectively, after 3 weeks of storage at 60 °C. These results illustrate that rosemary extracts exhibited very strong antioxidant activity, almost equal to that of synthetic antioxidants (BHA and BHT).     

Effect of cold press and soxhlet extraction systems on fatty acid,tocopherol contents,and phenolic compounds of various grape seed oils

In this study, fatty acids, tocopherol contents, and phenolic compounds of the grape seed oils obtained with cold‐pressed and soxhlet extraction systems from several grape seeds were investigated. Linoleic acid contents of cold‐pressed oils varied between 59.61 and 72.13%. In addition, linoleic acid contents of oils obtained with soxhlet system changed between 58.51 and 71.17%. While α‐tocotrienol contents of oil samples extracted with cold‐pressed change between 13.21 and 34.71 mg/100 g, α‐tocotrienol contents of oils obtained by soxhlet system in all grape varieties varied between 8.89 and 33.89 mg/100 g. In addition, while ?‐tocotrienol contents of cold‐pressed oils range from 15.47 to 39.95 mg/100 g, ?‐tocotrienol contents of soxhlet extraction oils in all grape varieties were determined between 13.47 and 35.75 mg/100 g. Both systems' oils are rich in catechin, gallic acid, and chlorogenic acid. While catechin contents of cold‐pressed oils change between 427.80 and 847.14 mg/kg, catechin contents of soxhlet extraction oils in all grape seeds ranged from 537.11 to 836.88 mg/kg.

Practical applications

Cold‐pressed grape seed oil stands out as a suitable alternative to other commonly used vegetable oils because of its higher amounts of essential fatty acid, and many others bioactive compounds. Grape seed oil is being used in various fields such as cosmetics and cooking. Because the cold‐pressing does not need both heat and chemical treatments, cold‐pressed oils are being preferred for natural and safe food products by consumer. The consumption of vegetable oils rather than solid fats is crucial to maintaining health. As known, grape seed oil is an environment friendly oil due to a by‐product of wine and grape juice‐making processes.     

Heated-air drying of oilseeds

This paper describes experimental work on the drying of oilseeds. Resistance to air flow and drying rates, parameters needed for oilseed drier design, were measured. Safe drying temperatures were deter,ined in a small batch fluidized bed. Some sealed tube heating tests were also perforrned for comparison. Quality assessment was based on the effect of drying conditions on the germination of the seed and on the free fatty acid content and peroxide value of the extracted oil. Colour of the oil was also measured before and after a heat bleach test using a photometric method.Quality results indicate that germination is affected by heat above a critical drying air and seed temperature. For sunflower seed, safe drying air temperatures of 65, 60 and 55°C were obtained for initial moisture contents of 12, 14 and 16% respectively. For rapeseed, an inlet air temperature of 60°C caused no loss of germination for each initial moisture content. However, sealed tube heating of 16% m.c. sunflower and rapeseed at 60°C for 4 hr completely killed the seeds. Free fatty acid content and peroxide value were not significantly changed by the heat treatments in all cases, and oil colour after heat bleaching generally showed some improvement up to an air temperature of 70°C. At 80°C, however, substantial darkening of sunflower oil was observed.     

Moisture content/relative humidity equilibrium of high-oil and confectionery type sunflower seed

Adsorption and desorption moisture equilibrium (m.c./e.r.h.) was determined for high-oil and confectionery type sunflower seeds. The seeds were exposed to various relative humidities which were controlled with environmental chambers. The equilibration data for both seed types were determined at 10 and 20°C. The two seed types yielded almost identical adsorption and desorption moisture curves at 10°C which indicated that seed physical and chemical properties had little effect on m.c./e.r.h. at this temperature. The “hysteresis effect” was evident at 10°C, desorption equilibrium moisture levels being higher than adsorption for both seed types. There was no apparent “hysteresis effect” in seed equilibrated at 20°C. At the higher temperature, the confectionery seed equilibrated to higher moisture levels than did the high-oil type, thus hull to kernel weight ratio, hull thickness, and oil content could affect m.c./e.r.h. at 20°C     

Optimization of Hull‐Less Pumpkin Seed Roasting Conditions Using Response Surface Methodology

Abstract: Response surface methodology (RSM) was applied to optimize hull‐less pumpkin seed roasting conditions before seed pressing to maximize the biochemical composition and antioxidant capacity of the virgin pumpkin oils obtained using a hydraulic press. Hull‐less pumpkin seeds were roasted for various lengths of time (30 to 70 min) at various roasting temperatures (90 to 130 °C), resulting in 9 different oil samples, while the responses were phospholipids content, total phenols content, α‐ and γ‐tocopherols, and antioxidative activity [by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) free‐radical assay]. Mathematical models have shown that roasting conditions influenced all dependent variables at P < 0.05. The higher roasting temperatures had a significant effect (P < 0.05) on phospholipids, phenols, and α‐tocopherols contents, while longer roasting time had a significant effect (P < 0.05) on γ‐tocopherol content and antioxidant capacity, among the samples prepared under different roasting conditions. The optimum conditions for roasting the hull‐less pumpkin seeds were 120 °C for duration of 49 min, which resulted in these oil concentrations: phospholipids 0.29%, total phenols 23.06 mg/kg, α‐tocopherol 5.74 mg/100 g, γ‐tocopherol 24.41 mg/100 g, and an antioxidative activity (EC₅₀) of 27.18 mg oil/mg DPPH. Practical Application: A well‐defined roasting process is very important for the food industry to be able to produce pumpkin seed oil with desirable nutritive and chemical characteristics of this unique salad oil, which changes during the roasting. This study contributes to the knowledge of a product design process for the roasting conditions of naked pumpkin seeds based on results that have demonstrated that an increase in roasting temperature significantly increased the biochemical values and antioxidant properties of the obtained virgin oils.     

Modulation of salt (NaCl)‐induced effects on oil composition and fatty acid profile of sunflower (Helianthus annuus L.) by exogenous application of salicylic acid

BACKGROUND: Salicylic acid (SA) is a potential endogenous plant hormone that plays an important role in plant growth and development. Since sunflower yield and its seed oil yield are adversely affected by salinity, in this study the role of SA in modulating salt (NaCl)‐induced effects on various yield and oil characteristics of sunflower was investigated. For this purpose a greenhouse experiment comprising two sunflower hybrid lines (Hysun‐33 and SF‐187), two NaCl levels (0 and 120 mmol L^?1) and four SA levels (0, 100, 200 and 300 mg L^?1) was conducted. RESULTS: Salt stress markedly reduced yield, oil content, linoleic acid and δ‐tocopherol in both sunflower lines, while it increased linolenic acid, palmitic acid, stearic acid and α‐ and γ‐tocopherols. However, increasing levels of foliar‐applied SA resulted in improved achene yield and hundred‐achene weight in both lines. Foliar‐applied SA caused a significant decrease in oil stearic acid and α‐ and γ‐tocopherols in both lines under non‐saline and saline conditions. CONCLUSION: Salt‐induced harmful effects on achene yield and oil characteristics of sunflower could be alleviated by exogenous application of SA. High doses of SA caused a marked increase in sunflower achene oil content as well as some key fatty acids. Copyright © 2010 Society of Chemical Industry     

A chemiluminescence study of the oxidation of vegetable oils and model compounds and the effects of antioxidants

Chemiluminescence was used to study the course of oxidation of sunflower oil samples at a number of temperatures between 70 and 121°C. The induction time was determined for each sample and used to estimate the shelf life of the oils at 25°C. In addition, Chemiluminescence during oxidation in air on alumina at 80°C was used to study both sunflower oil and, as a model compound, methyl linoleate with and without added artificial antioxidants. By using the method of inhibitors, the reaction rate and level of hydroperoxide were determined. It was also possible to determine the level of naturally occurring antioxidant in the vegetable oil.     

Determination of caffeic and chlorogenic acids and their derivatives in different sunflower seeds

Five different genotypes (Tesoro, Marko, Clip, Vyp‐70 and Nanta) of sunflower seeds were studied and the phenolic compositions of their kernel and hull were characterised by HPLC and MS techniques. The main phenolic compounds present in both the kernel and hull are chlorogenic acid, caffeic acid and two caffeoylquinic derivatives. Both derivatives were characterised by partial alkaline hydrolysis and LC/MS. The four phenolic compounds present in the kernel ranged from 94.6% (genotype Clip) to 99.3% (genotype Marko) of the total phenolic compounds of the whole seed. Therefore the dehulling of the seed scarcely improves its nutritional value. © 2000 Society of Chemical Industry     

水酶法提取葵花籽油工艺及机理

本研究是以脱酚的葵花籽仁为原料,主要研究了葵花籽粉碎粒径及各种水酶法提取条件等对葵花籽油提取率的影响;采用激光共聚焦显微镜(Contocal Laser Scanning Microscope,CLSM)对葵花籽粉碎过程及各相进行了表征,明确了较佳工艺条件的内在机制。研究表明,经进一步精粉碎,粒径能够达19.68 μm,游离油得率大幅提高。水酶法提葵花籽油的较佳工艺条件为:料液比1:5(w/v),添加1.5%的碱性蛋白酶Protex 6L反应2 h。该条件下,葵花籽游离油得率达到92.48%。CLSM证明精粉碎得到的葵花籽物料比剪切粉碎的尺寸更小、更均匀。水酶法提取的葵花籽油在主要理化指标上达到了冷榨一级油的标准,其反式脂肪酸显著低于市售低温压榨葵花籽油。水酶法提取的油品质更好,得油率更高,有明显的优势。     

Analysis of pomegranate seed oil for the presence of jacaric acid

BACKGROUND: Pomegranate seed oil is predominantly composed of triglycerides containing unsaturated fatty acids, including high levels of conjugated linolenic acids (CLnAs). The major CLnA component, punicic acid, is known to possess biological activity. Consequently, it is desirable to obtain a detailed characterisation of pomegranate seed oil fatty acid profiles, including molecules potentially co‐eluting with punicic acid, such as jacaric acid. RESULTS: Conjugated fatty acid profiles of a commercial sample of cold pressed pomegranate seed oil were characterised in detail by both gas chromatography of methyl esters and by ¹³C NMR spectroscopy. The methylation procedures were found to be critical for determination of accurate fatty acid profiles. GC analysis was unable to resolve jacaric acid from punicic acid, the major fatty acid present in pomegranate seed oil. To establish the presence or absence of jacaric acid, ¹³C NMR was employed. CONCLUSION: This is the first study to investigate pomegranate seed oil for the presence of jacaric acid. Punicic acid, eleostearic acid, and catalpic acid were confirmed by ¹³C NMR, but jacaric acid was not found. Thus, we have shown that punicic acid levels may be accurately measured by gas chromatography alone in pomegranate seed oil. Copyright © 2009 Society of Chemical Industry     

基于气相色谱法的食用向日葵葵籽含油量及脂肪酸组成研究

收集12类不同品种食用向日葵葵籽为测试材料,测定不同样品千粒重、出仁率与含油量,在食用向日葵葵籽样品中滴加甲酯化剂进行气相色谱检测,依据标准品总峰面积确定食用向日葵葵籽出油率,利用气相色谱法检测材料样品脂肪酸组成及相对含量。分析结果显示:食用向日葵葵籽千粒重为43.37 g~205.87 g、出仁率为43.84%~75.59%;食用向日葵葵籽含油量33.08%~41.26%,出油率与含油量相比差距为1%左右。食用向日葵葵籽样品脂肪酸甲酯总离子图内出峰时间说明脂肪酸组成成分主要包括棕榈酸、硬脂酸、油酸以及亚油酸,其中亚油酸相对含量较高,基本达到50%以上。