SEPARATION of CHOLESTEROL FROM BUTTEROIL USING QUILLAJA SAPONINS. 1. EFFECTS of PH, CONTACT TIME and ADSORBENT

The technical feasibility of separating cholesterol from butteroil by contacting it with aqueous solutions of Quillaja saponaria saponins followed by separation of the cholesterol-saponin complex was studied. Alternative processes and controls compared were (1) Water Control (W): butteroil was contacted with pure water; (2) Reaction (R): butteroil was contacted with aqueous solution of saponins; (3) Adsorption Control (A): butteroil was contacted with water, diatomaceous earth was then added; (4) Reaction + Adsorption (R+A): diatomaceous earth was added to the Reaction medium (from 2); (5) Reaction + Washing (R+W): the aqueous phase resulting from Reaction (2) was discarded and pure water contacted with the fat. the last step in all the above processes and controls was the separation of the fat phase where cholesterol was determined. Statistical analysis indicated that the Adsorption Control did not yield any significant cholesterol reduction over the Water Control, while all other processes gave significant reduction. the order of cholesterol separation observed was R+A > R+W > R. the levels of cholesterol reduction were significantly affected by pH of quillaja solution and amount of adsorbent used; the time of contact with quillaja solution had no significant effect over the range investigated. These results indicate the technical feasibility of reducing the cholesterol levels of butteroil using food grade quillaja saponins.     

Effect of saponins on the physical characteristics, composition and quality of akara (fried cowpea paste) made from non-decorticated cream cowpeas

Changes in the foaming capacity and viscosity of cowpea paste, affected by the addition of saponins, were investigated, as well as the subsequent effect on the texture and oil content of Akara (fried cowpea paste). Two saponins, Quillaja and Yucca, were used. Results showed a significantly greater decrease in the specific gravity after whipping (39.9-52.9%), of the paste prepared with saponins compared to that prepared without saponins (25.1-32.9%). This demonstrated the increase in foaming capacity of the paste prepared with saponins. The results also showed a higher foaming capacity for the Yucca saponin compared with the Quillaja saponin. Subsequently, there was a significant decrease in the apparent viscosity of the paste prepared with saponins and a decrease in the firmness (6.51-7.78 N) of the fried product compared to that prepared without saponins (10.89-11.58 N). These results suggest that saponins can be used to increase the foaming capacity of cowpea paste resulting in a more desirably soft, spongy-textured product. There was a significant increase in the fat content of the samples produced with saponins (25.1-42.0 g/100 g) compared to the control (18.8-19.6 g/100 g) due to the formation of more air spaces in the cowpea paste.     

Continuous reactor for enzymic glycerolysis of butteroil in the absence of solvent

A continuous reactor was evaluated for lipase-mediated glycerolysis of butteroil in the absence of solvent. Lipase (from Pseudomonas cepacia) was immobilized by adsorption, followed by covalent coupling with glutaraldehyde, on a polypropylene sheet which was placed inside the reactor in a spiral wound configuration (axial-annular flow). Substrate feedstock was 2:1 (w/w) butteroil/glycerol and included 1% (w/w) lecithin to promote phase homogeneity. Reactor temperature was maintained at a minimum of 40 °C to prevent substrate/product solidification and attendant reactor fouling. Glycerolysis was found to be most efficacious at 45–55 °C, with 10.5% aqueous glycerol, and at reactor space times approaching 10 h. Under these conditions, >70% butteroil triacylglycerols were converted into a product mixture containing about 70% diacylglycerol and monoacylglycerol at a mass ratio of 2.1–2.2:1.     

Action of amorphous diatomaceous earth against different stages of the stored product pests Tribolium confusum, Tenebrio molitor, Sitophilus granarius and Plodia interpunctella

Environmental and human health problems associated with the use of synthetic pesticides have prompted the demand for non-polluting, biologically specific insecticides. The current study tested the use and action of diatomaceous earth against several stored product pests. Fossil Shield(R) applied to wooden plates was lethal to adult Tenebrio molitor and Tribolium confusum, but larvae of the mealworm were unaffected. Beetles died within 14 days exposure in the absence of food to a dose of 2 and 4 g/m(2), but mortality was reduced in those fed grain bran. Fossil Shield(R) was lethal to first instar larvae of Plodia interpunctella, but not lethal to older larval stages. Two-week old larvae of T. confusum were more sensitive to diatomaceous earth than P. interpunctella at the same age. Contact with diatomaceous earth caused adult Sitophilus granarius, T. molitor and T. confusum to lose weight and reduced their water content, suggesting disruption of "the water barrier". Death of stored product insects treated with diatomaceous earth decreased with increased r.h., due to reduced transpiration through the cuticle. High r.h. delays, or above 60% can prevent, the drying action of diatomaceous earth.     

Physical Properties of 20% Milk Fat Reformulated Creams Manufactured from Cholesterol-reduced Butteroil

A cholesterol-reduced butteroil was emulsified with various milk-derived components into three different cream formulations having 20% milk fat. Viscosity, creaming stability, and feathering stability of the cream formulations and a control homogenized at two pressures (10.2/3.4 MPa; 13.6/3.4 MPa) were measured over 2 wk. All creams demonstrated non-Newtonian fluid behavior at 7 °C. Apparent viscosity varied with formulation (p ≦ 0.05). Creaming stability was affected by formulation, homogenization pressure, and storage time (p ≦ 0.05). Feathering was unaffected by any treatments. The formulation using buttermilk and butter-derived aqueous phase best simulated viscosity and creaming stability of the control cream.     

天然皂苷自组装及其对食品胶体功能特性影响的研究进展

皂苷（Saponin）作为广泛存在于天然植物界中的一大类糖苷近年来受到广泛关注。在分子结构上,天然皂苷是以三萜或甾体苷元的疏水基为支架并附着亲水性糖链所构成,从而表现出高界面活性。天然皂苷分子结构的多样性不仅使其具有生物活性和独特的物理化性质,促进其在食品、化妆品以及其他领域中的广泛应用。本研究结合近年来对天然皂苷结构特性、自组装和界面特性的研究,试图探究皂苷结构如何影响其在水相、气-水界面、油-水界面和固-液界面的组装行为,以及其对食品胶体功能特性的影响。自组装和界面结构可能因植物来源和分子结构而不同：具有三萜结构的皂苷最有助于形成粘弹性界面膜,产生稳定的食品胶体;而甾烷类皂苷更倾向于具有特殊的生理活性。其中天然皂皮皂苷表现最为优异,已被证实可形成稳定的胶束、纳米乳液、乳液凝胶和泡沫等用于生物活性物质的输送,目前已被包括中国、美国和欧盟等多数国家批准用于食品。     

Processing effects on physicochemical properties of creams formulated with modified milk fat

Type of thermal process [high temperature, short time pasteurization (HTST) or ultra-high temperature pasteurization (UHT)] and homogenization sequence (before or after pasteurization) were examined for influence on the physicochemical properties of natural cream (20% milk fat) and creams formulated with 20% low-melt, fractionated butteroil emulsified with skim milk, or buttermilk and butter-derived aqueous phase. Homogenization sequence influenced physicochemical makeup of the creams. Creams homogenized before pasteurization contained more milk fat surface material, higher phospholipid levels, and less protein at the milk fat interface than creams homogenized after pasteurization. Phosphodiesterase I activity was higher (relative to protein on lipid globule surface) when cream was homogenized before pasteurization. Creams formulated with skim milk and modified milk fat had relatively more phospholipid adsorbed at the milk fat interface. Ultra-high-temperature-pasteurized natural and reformulated creams were higher in viscosity at all shear rates investigated compared with HTST-pasteurized creams. High-temperature, short time-pasteurized natural cream was more viscous than HTST-pasteurized reformulated creams at most shear rates investigated. High-temperature, short time-pasteurized creams had better emulsion stability than UHT-pasteurized creams. Cream formulated with buttermilk had creaming stability most comparable to natural cream, and cream formulated with skim milk and modified butteroil was least stable to creaming. Most creams feathered in a pH range of 5.00 to 5.20, indicating that they were moderately stable to slightly unstable emulsions. All processing sequences yielded creams within sensory specifications with the exception of treatments homogenized before UHT pasteurization and skim milk formulations homogenized after UHT pasteurization.     

Monoacylglycerol Production from Butteroil by Glycerolysis with a Gel-Entrapped Microbial Lipase in Microaqueous Media

Reaction parameters were optimized to support polyethyleneglycol-based and polypropyleneglycol-based gel-entrapped lipase-mediated glycerolysis of butteroil to yield monoacylglycerol. Single liquid-phase reactive mixtures contained 25% (w/w) butteroil dissolved in t-butanol, to which glycerol and water was added. Optimum reaction conditions were 35–40 °C, and 5–10 mg enzyme reagent and 0.10g glycerol/mL substrate solution. Optimum acyl group:glycerol molar ratio was about 0.64. The optimum water content was dependent on glycerol content and was about 6% (w/w) of the glycerol at 0.10g glycerol/mL substrate solution. The gel-entrapped lipases had half-lives of about 35–46 cycles of 72 hr each.     

一种水包油包胶型乳液的制备及其在乳化肠中的应用

以结冷胶和无水氯化钙为内水相凝固剂,酪蛋白酸钠为外水相乳化剂,制备一种水包油包胶（S/O/W）型 乳液。以多重乳液粒径和分布为指标,研究酪蛋白酸钠添加量对S/O/W型多重乳液加工适应性的影响。结果表明： 正交试验得到S/O型单重乳液最佳制备条件为：内水相中结冷胶添加量0.2%、无水氯化钙添加量0.5%;内水相乳化 剂聚甘油蓖麻醇酯添加量2.5%;油相为精炼猪油,油水体积比3∶2;剪切速率17 500 r/min,剪切时间1.5 min。将制 得的S/O型单重乳液与不同添加量酪蛋白酸钠混合制得S/O/W型多重乳液。当酪蛋白酸钠添加量0.1%时,S/O/W型 多重乳液粒径符合加工要求,且贮藏、热处理、剪切稳定性较好。以多重乳液替代猪脂肪制备的低脂乳化肠与高脂 （精炼猪油含量20%）乳化肠外观不存在明显差异;微观结构观察结果表明,多重乳液在乳化肠中包裹良好、分布 均匀。     

Effect of saponins on the foam/flow properties of paste and physical characteristics of akara made from decorticated black‐eyed cowpeas

Akara, a deep‐fat‐fried cowpea paste product, is a popular snack food in West Africa. Foaming capacity of the cowpea paste is important for achieving a spongy light‐textured fried product. The effect of two saponins, Yucca and Quillaja, on the foaming capacity of cowpea paste was investigated. Results showed that an increase in the amount of saponin added (1, 2, 4%) resulted in a decrease in specific gravity and apparent viscosity of the cowpea paste. Addition of saponin also significantly reduced the firmness and increased the cohesiveness of the akara compared with the control. Akara made using the Quillaja saponin was less firm and more cohesive than akara made using the Yucca saponin. An increase in the amount of saponin added to the cowpea paste resulted in a darker (lower L*) and browner colour of akara. However, akara containing 1% Yucca saponin had similar colour attributes to the control but was less firm and more cohesive. Copyright © 2005 Society of Chemical Industry     

Physical properties of cream reformulated with fractionated milk fat and milk-derived components

Emulsifying properties of milk-derived components influence the physical characteristics of reformulated creams. Fractionated butter oils with different melting ranges (low-melt: 10 to 25 degrees C; medium-melt: 25 to 35 degrees C) were recombined into fluid dairy systems using skim milk, or sweet buttermilk and butter-derived aqueous phase to manufacture 20% milk fat creams. Separation temperature (49 degrees C or 55 degrees C) in obtaining emulsifying components was examined for its effect on physical properties of pasteurized reformulated creams. Rate of creaming, viscosity, feathering, and sensory characteristics of reformulated and natural creams stored at 3.3 degrees C were evaluated over a 13-d period. Creaming rate of reformulated and natural creams was unaffected by formulation and was most influenced by duration of storage. Melting characteristics of butter oils influenced viscosity at some shear rates. With the exception of natural cream, all formulations were consistent in apparent viscosity during the 2-wk storage period. All creams feathered in a pH range of 4.70 to 5.20 and were classified as moderately stable to slightly unstable. All reformulated and natural creams met sensory quality specifications with the exception of creams formulated with skim milk and lower melting range butteroil. Creams formulated with buttermilk, butter-derived aqueous phase, and lower-melting range butter oil most closely mimicked natural creams with regard to sensory quality and viscosity.     

Hydrolysis of Milk Fat with Lipase in Reversed Micelles

Enzymatic hydrolysis of milk fat was studied in a reversed-micelle system consisting of lecithin, water (1% total volume) and butteroil. Candida cylindracea lipase entrapped in the water pools of reversed micelles hydrolyzed surrounding triglycerides. The optimum temperature for enzyme activity was 55°C with an activation energy of 15.4 kcal/mole, while maximum enzyme activity was observed between pH 4 to 6. The molar ratio of water to surfactant (R value) in the system influenced enzyme activity with maximum activity at R = 10. Enzyme activity also increased with increasing surfactant or enzyme concentration.     

Effects of Prolonged and Adverse Storage Conditions on Levels of Cholesterol Oxidation Products in Dairy Products

The effects of normal and adverse environmental holding conditions on the formation of cholesterol oxidation products (COPS) in powdered cheeses and salted and unsalted butteroil were investigated. Little or no change in COPS levels was noted in a variety of powdered dairy products stored at 4, 21, or 38°C for up to 6 months. Storage for 18 mo at 4°C resulted in a three-fold increase in the levels of COPS. Cheddar cheese powder continuously exposed to light (1611 lx) displayed increases in α-epoxide and 7-ketocholesterol through week 3, thereafter declining to a level at week 9 of about one-half of that seen at week 3. Continuous heating of butteroil (110°C) caused large increases in COPS' levels, with unsalted butteroil exceeding levels found in salted butteroil by 2- to 3-fold.     

卡亚茶水提物辅助调节血脂功能作用研究

目的:研究卡亚茶水提物的辅助降血脂作用。方法:将50只小鼠随机分成空白对照组(普通饲料)、阴性对照组(高脂饲料)和高、中、低剂量组(卡亚茶水提取物+高脂饲料),分笼喂养30d,测定小鼠体重、肝重、肝脏指数、血清总胆固醇(TC)、血清三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)和高密度脂蛋白胆固醇(HDL-C),并观察肝脏组织病理学变化。结果:卡亚茶水提取物可缓解高脂饲料喂养小鼠体重、肝重和肝脏指数的增加,降低高脂小鼠肝组织中脂肪细胞量,中剂量组小鼠血清TC、TG和LDL-C显著低于阴性对照组(p<0.05),HDL-C显著高于阴性对照组(p<0.05)。结论:适当浓度的卡亚茶水提取物有辅助降血脂作用。     

Interactions between food components in ice cream. Part 1: unfrozen emulsions

Ice cream was manufactured on a pilot plant and the structure of the emulsion was estimated in terms of droplet size distribution and protein composition of the aqueous phase after homogenization (two stages: 19 MPa + 3 MPa, 70°C) and after ageing ( 18 h, 4°C). Four different factors were studied: the nature of the milk protein [skim milk powder (SMP), skim milk replacer (SMR) or whey protein concentrate ( WPC) ], the nature of the emulsifier (saturated monoglycerides or Sugin Fl50, which is apolysorbate 80-based emulsifier) and its concentration (0.17–0.67% w/w for Sugin F150; 0.20–0.54% wlw for saturated monoglycerides), and the amount of butter oil (8–12% wlw). Freshly homogenized mixes containing either SMP or an SMR were stable during the ageing stage, irrespective of the nature and the concentration of the emulsifier. WPC-based mixes, however, were destabilized after homogenization: this destabilization was found to be flocculation only, which shows that whey proteins are efficient against coalescence. The quantity of adsorbed protein per surface unit was systematically higher for SMP mix than for both SMR and WPC. After the ageing stage, the structure of the mixes containing monoglycerides or WPC + polysorbate 80 remained unchanged. However, polysorbate 80 used in combination with both SMP and SMR led to a destabilization of the mix during the ageing stage: this destabilization was found to depend upon the mass/surface ratio of polysorbate 80 to butteroil.     

响应面法优化托盘根总皂苷提取工艺及抗氧化活性研究

In this study, the extraction process of total saponins from Rubus crataegifolius Bunge. roots was investigated and optimized by response surface method. The effects of ethanol concentration, extraction time and solid-liquid ratio on the extraction rate of total saponins from pallets were investigated. The results showed that the optimal extraction conditions of the total saponins from the pallets were: extraction time 2 h, ethanol concentration 71%, liquid-solid ratio 28:1 mL/g, the predicted value was 3.49%. Under these conditions, the extraction rate of total saponins from R. crataegiolius Bunge. roots was 3.366%. The IC₅₀ (mg/mL) values of total saponins extract from R. crataegifolius Bunge. roots against DPPH·, ABTS+· and superoxide anion free radicals were 0.0782, 0.277 and 0.9954 mg/mL, respectively. Therefore, the response surface method to optimize the extraction process of total saponins from R. crataegifolius Bunge. roots was effective, reliable, stable and feasible, and this article would provide scientific basis for the development and utilization of total saponins from pallets as natural antioxidants.     

Improving the quality of fried oils by using different filter aids

The present study aimed to improve the quality of fried soybean, sunflower, palm and cottonseed oils. Synthetic (Magnesol XL) and natural (diatomaceous earth and kaolin) filter aids were used at various levels (1, 2 and 4%) to adsorb the secondary oxidation products of the oil. The metal patterns (the cations Si, Mg, Ca, Fe, Na, K, Al, Cu, Mn, Zn and the anions CO₃^2?, HCO₃^?, Cl^?, NO₃^?, NO₂^?, SO₄^2?) of Magnesol XL, diatomaceous earth and kaolin were determined. Some physical and chemical properties (refractive index, viscosity, colour, foam height, acid value, peroxide value, thiobarbituric acid value, iodine value, and conjugated diene and polymer contents) of non‐fried, fried and fried–treated soybean, sunflower, palm and cottonseed oils were determined. The frying process was performed at 180 °C ± 5 °C for 12 h continuous heating. The fried oils were treated with the synthetic and natural filter aids at 105 °C for 15 min. The results indicate that Magnesol XL, diatomaceous earth and kaolin contained Si + Mg, Si + Ca and Si + Al, respectively, as the basic metals. Frying soybean, sunflower, palm and cottonseed oils led to significant increases in refractive index, colour, foam height, viscosity, acid value, peroxide value, TBA value, conjugated diene and polymer contents and decrease in iodine value. Treatment of fried oils with Magnesol XL, diatomaceous earth and kaolin at the 1, 2 and 4% levels greatly improved the quality of fried oils. These findings indicate the high efficiency of the filter aids used in the present study in adsorbing the products of oil degradation. Copyright © 2006 Society of Chemical Industry     

热反应制备天然鸡肉香精配方的改进及其风味成分的研究

本研究对热反应制备天然鸡肉香精的配方进行了优化,研究了硫胺素(VB1)、鸡脂、HVP(水解植物蛋白)和非含硫氨基酸对产物风味的影响,确定了各配料的最佳添加量:硫胺素3.37g,鸡脂3g,HVP粉4g,甘氨酸:丙氨酸(摩尔比)=1:2,非含硫氨基酸:半胱氨酸(摩尔比)=1:1。利用HS-SPME法,通过GC-MS对煮鸡汤和美拉德反应产物的风味成分进行了分析比较。煮鸡汤中鉴定出31种挥发性成分。美拉德热反应产物中鉴定出56种挥发性成分,主要涵盖了醇类、醛类、酮类、酯类、呋喃、噻唑、吡嗪、吡咯、吡啶、芳香族、烷烃、烯烃、醚等共13类以上的化合物,其中有17种挥发性成分与煮鸡汤中的挥发性成分相同;壬醛、2-戊基呋喃、4-甲基-5-羟乙基噻唑等一些具有肉香和鸡肉特征香气的挥发性成分也被检出。     

Effect of pre-soaking whole pelagic fish in a plant extract on sensory and biochemical changes during subsequent frozen storage

Plant extract treatments have largely shown a positive effect on inhibiting the quality loss during the frozen storage of minced and filleted fish products. In the present case, the effect of a plant extract on a whole fish product was checked. For it, whole fresh horse mackerel was soaked in a commercial extract solution during 60 min and then kept frozen up to 12 months at −20 °C. Sampling was carried out on the initial material and at months 1, 3, 5, 7, 9 and 12. Two parallel experiments consisting on untreated fish (Blank Control) and water treated fish (Water Control) were carried out in the same conditions. Lipid damage was measured by lipolysis development (free fatty acid formation), rancidity development (conjugated dienes (CDs), secondary oxidation compounds, fluorescent compounds and cholesterol oxides) and sensory (odour, firmness and colour) analyses. As a result of the previous plant extract treatment, better odour and colour scores were obtained that led to a larger shelf-life time (7 months) than in the two controls (5 months), according to the sensory analysis. Water treatment of fish (Water Control) also showed some better results in sensory (odour and colour) analysis than the Blank Control, that could be related to the elimination of some prooxidant molecules included in fish. Some biochemical indices (CDs and free fatty acids) also provided a damage inhibition (P<0.05) in the 9-12 months period as a result of the plant treatment and water treatment; however, fluorescence and cholesterol oxide detections did not show differences (P>0.05) when compared to the Blank Control. The present experiment provides promising results for soaking a pelagic whole fish in an aqueous plant extract as a previous step to its commercialization as a frozen product.