Response surface methodology and multivariate analysis of equilibrium headspace concentration of orange beverage emulsion as function of emulsion composition and structure

The influence of emulsion composition (i.e. Arabic gum, xanthan gum and, orange oil) and structural emulsion properties (i.e. average droplet size and apparent viscosity) on equilibrium headspace concentration of beverage emulsions was investigated. Increase in average droplet size led to increase the equilibrium headspace concentration of more hydrophilic volatile compounds (i.e. lower log P) such as ethyl acetate and octanal, but decrease in more hydrophobic volatile compounds such as 3-carene, myrcene and limonene. In most cases, apparent viscosity had significant positive effect on equilibrium headspace concentration. Principle component analysis (PCA) score discriminated the beverage emulsions containing the same orange oil content but different contents of emulsifiers in different classes, thus indicating the significant (p < 0.05) effect of emulsifier fraction on equilibrium headspace concentration. Beverage emulsion containing 22.2% (w/w) Arabic gum, 0.52% (w/w) xanthan gum and 14.21% (w/w) orange oil was estimated to provide the highest equilibrium headspace concentration.     

Optimisation of freeze drying conditions for purified serine protease from mango (Mangifera indicaCv. Chokanan) peel

This study investigated the possible relationship between the encapsulation variables, namely serine protease content (9–50 mg/ml, X₁), Arabic gum (0.2–10% (w/w), X₂), maltodextrin (2–5% (w/w), X₃) and calcium chloride (1.3–5.5% (w/w), X₄) on the enzymatic properties of encapsulated serine protease. The study demonstrated that Arabic gum, maltodextrin and calcium chloride, as coating agents, protected serine protease from activity loss during freeze-drying. The overall optimum region resulted in a suitable freeze drying condition with a yield of 92% for the encapsulated serine protease, were obtained using 29.5 mg/ml serine protease content, 5.1% (w/w) Arabic gum, 3.5% (w/w) maltodextrin and 3.4% (w/w) calcium chloride. It was found that the interaction effect of Arabic gum and calcium chloride improved the serine protease activity, and Arabic gum was the most effective amongst the examined coating agents. Thus, Arabic gum should be considered as potential protection in freeze drying of serine protease.     

Effect of Arabic gum,xanthan gum and orange oil on flavor release from diluted orange beverage emulsion

The influence of main emulsion components namely Arabic gum (13–20% w/w), xanthan gum (0.3–0.20% w/w) and orange oil (10–14% w/w) on semi-quantitative headspace analysis of target volatile flavor compounds released from a model orange beverage (diluted orange beverage emulsion) was evaluated by using a three-factor circumscribed central composite design (CCCD). For optimization procedure, the peak area of 13 volatile flavor compounds (i.e. ethyl acetate, α-pinene, ethyl butyrate, β-pinene, 3-carene, myrcene, limonene, γ-terpinene, octanal, decanal, linalool, neral and geranial) were considered as response variables. The response surface analysis exhibited that the significant (p < 0.05) second-order polynomial regression equations were successfully fitted for all response variables except for ethyl butyrate. A satisfactory coefficient of determination (R²) ranged from 0.831 to 0.969 (>0.8) was obtained for the response variables studied. No significant (p > 0.05) lack of fit was indicated for the reduced models except for the models fitted for limonene and linalool. This observation confirmed an accurate fitness of the reduced response surface models to the experimental data. The multiple response optimizations indicated that an orange beverage emulsion containing 15.87% (w/w) Arabic gum, 0.5% (w/w) xanthan gum and 10% (w/w) orange oil was predicted to provide the minimum overall flavor release.     

Rheological behavior and stability of d-limonene emulsions made by a novel hydrocolloid (Angum gum) compared with Arabic gum

Our goal was to evaluate emulsion stability, droplet size analysis and rheological behavior of the emulsions prepared by a native biopolymer namely Angum gum (An) compared with Arabic gum (Ar) stabilized emulsions. After gum extraction, gum dispersions with maltodextrin were prepared in water (in 1-5% concentrations) and emulsified with 5% and 10% d-limonene using high pressure homogenization. Statistical analysis revealed a significant influence of gum type and gum concentration on emulsion stability at α = 0.05. Flavor level was not important statistically in emulsion stability but it was the only factor with a significant influence (P < 0.05) on surface tension of the emulsions. The results showed that Angum gum was superior to Arabic gum in stabilizing emulsions during storage. Also, rheological data revealed that Angum gum-emulsions’ behavior was following the Herschel-Bulkley model with higher viscosities compared to Arabic gum emulsions, which could be the main reason of higher emulsion stabilities with this novel hydrocolloid.     

Characterization of the influence of main emulsion components on the physicochemical properties of orange beverage emulsion using response surface methodology

The present work was conducted to investigate the influence of main emulsion components, namely Arabic gum (7–13% w/w), xanthan gum (0.1–0.3% w/w) and orange oil (6–10% w/w) contents on physical stability, viscosity, cloudiness and conductivity of orange beverage emulsion. In this study, 20 orange beverage emulsions were established based on a three-factor central composite design (CCD) involving 8 factorial points, 6 axial points and 6 center points. The main objective of the present study was to determine an optimal concentration level of main emulsion components leading to an optimum orange beverage emulsion with desirable physicochemical properties. In general, all response surface models were significantly (p<0.05) fitted for describing the variability of physical stability, viscosity, conductivity and cloudiness as a nonlinear function of the content of main emulsion components. More than 84% of the variation of physicochemical properties of orange beverage emulsion could be explained as a function of the content of the main beverage emulsion components. In general, the orange oil content appeared to be the most significant (p<0.05) factor influencing all emulsion characteristics studied except for conductivity. From the optimization procedure, the overall optimal region leading to the desirable orange beverage emulsion was predicted to be achieved by the combined level of 13% (w/w) Arabic gum, 0.22% (w/w) xanthan gum and 10% (w/w) orange oil.     

Optimizing microencapsulation of peanut sprout extract by response surface methodology

This study was carried out to optimize conditions for peanut sprout extract microencapsulation by response surface methodology (RSM). The coating materials of microencapsulation were medium-chain triacylglycerol (MCT) for primary emulsion, and whey protein concentrates (WPC), maltodextrin (MD) and gum Arabic (AG) for secondary emulsion. The yield of microencapsulation of peanut sprout extract was investigated with respect to four variables (ratio of core and coating materials, concentration of primary emulsifier, ratio of W/O emulsion and secondary coating materials and concentration of secondary emulsifier) in RSM. The optimal conditions for microencapsulation of peanut sprout extract were 1:2 as the ratio of core material to coating material, 1.25% (w/v) of primary emulsifier concentration, 1:1.23 as W/O emulsion to secondary coating material, 1.21% (w/v) as secondary emulsifier concentration and 30% (w/w) as WPC concentration for spray drying. In conclusion, the microencapsulation of peanut sprout extract under the optimized conditions by RSM ensures the smaller size (3–7 μm) of microcapsules with the highest yield reaching to 98.74%.     

Application of Response Surface Modeling to Optimize Critical Structural Components of Walnut–Beverage Emulsion with Respect to Analysis of the Physicochemical Aspects

The application of walnut oil (WO) as a functional component in the production of beverage emulsion was investigated using response surface methodology (RSM). The effects of three critical structuring components (considered as independent variables), namely gum arabic (GA; 6–10% (w/w)), xanthan gum (XG; 0.10–0.30% (w/w)), and WO (3.5–6.5% (w/w)) on the turbidity loss rate, stability, size index, opacity, and pH (considered as dependent variables) of these emulsions, were studied. For each response parameter, a second-order polynomial model versus independent variables was determined and statistically obtained with high coefficient of determination values (R ²?>?0.96). Most significant (p?<?0.0001) effect was attributed to the linear function of WO in all reduced models. Numerical optimization defined the optimum formulation where the highest stability and opacity and the lowest turbidity loss rate, size index, and pH (GA content 10.0% (w/w), XG content 0.13% (w/w), and WO concentration 5.09% (w/w)) were expected. Under the optimum condition, the corresponding predicted response values for turbidity loss rate, stability, size index, opacity, and pH were predicted to be 0.366 Å/day, 99.40%, 0.599, 1.034, and 3.69, respectively. RSM analysis indicated good correlation between experimental and predicted values.     

The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI)

The effect of addition of flaxseed gum on the emulsion properties of soybean protein isolate (SPI) were investigated in this study. Flaxseed gum with 0.05-0.5% (w/v) concentration was used together with 1% (w/v) SPI to emulsify 10% (v/v) soybean oil. The emulsion was analyzed for emulsion activity (turbidity), stability, particle size, surface charge, and rheological properties. The turbidity and absolute zeta-potential values decreased initially by the addition of flaxseed gum and subsequently increased with further increase in the gum concentration to reach their peak around 0.35% (w/v) gum. The particle size of the emulsion decreased and reached a minimum value at 0.1% (w/v) gum concentration. Any increase in gum concentration beyond this value resulted into increase in the particle size. This study would help to widen the application of SPI and flaxseed gum mixture, and also contribute to the understanding of protein-gum interaction in emulsion.     

Influence of polysaccharides and storage during processing on the properties of mango seed kernel extract (microencapsulation)

Extracts from mango (Mangifera indica Linn.) cultivar Chok–Anan seed kernels were studied as active substances, since they are known as a good source of phenolic antioxidants with metal chelating and tyrosinase inhibitory activities. Response surface methodology (RSM) was used to investigate the effect of a combination of polysaccharides selected from gum arabic, maltodextrin and alginate on droplet size distribution, encapsulation efficiency (EE), stability and viscosity of W/O/W emulsions. In addition, the effects of stored emulsion on the properties of the encapsulated powder were studied. The results showed that there were interactions between polysaccharides which affected droplet size distribution, stability, viscosity and EE of multiple emulsions. The RSM showed a good fit to the proposed model with R² > 0.83, 0.79 and 0.69 for viscosity, stability and EE, respectively, with significant correlations (p < 0.05). The formulation which gave an optimal coating material was also a suitable coating mixture for preparation of encapsulated mango seed kernel extract powder. Moreover, if the polysaccharide combination is not appropriate for coating, the storage after emulsion preparation will have a greater effect on the properties of the encapsulated emulsion and powder.     

Study of emulsions stabilized with Phaseolus vulgaris or Phaseolus coccineus with the addition of Arabic gum, locust bean gum and xanthan gum

The properties of o/w emulsions stabilized with 1%w/v common bean (Phaseolus vulgaris L.), V or scarlet runner bean (P. coccineus L.), Coc extracted by isoelectric precipitation or ultrafiltration, at pH 7.0 and 5.5, with the addition of Arabic gum, locust bean gum, xanthan gum and a mixture of xanthan gum–locust bean gum (0.1 %w/v and 0.25 %w/v) are studied. The stability of emulsions was evaluated on the basis of oil droplet size, creaming, viscosity and protein adsorption measurements. The addition of Arabic gum, caused an increase in D[4,3] values and a decrease in the amount of protein adsorbed at the interface. The addition of locust bean gum in some emulsions reduced the amount of protein adsorbed. The addition of xanthan and to a less extend of the polysaccharide mixture, promoted a decrease in D[4,3]. So, emulsion stability was affected by the polysaccharide nature. Differences were also observed with respect to the protein nature, the method of its preparation and emulsion's pH. All polysaccharides enhanced the emulsions viscosity with xanthan and xanthan–locust bean gum exhibiting the higher values. V isolates and isoelectricaly precipitated isolates of both V, Coc showed higher viscosity values. The stability was enhanced by the increase of the viscosity of the continuous phase and the creation of a network, which prevents the oil droplets from coalescence.     

Emulsifying Properties of Angum Gum (Amygdalus scoparia Spach) Conjugated to β-Lactoglobulin through Maillard-Type Reaction

In this study, emulsifying properties of Angum gum were improved by covalent bonding with β-lactoglobulin (BLG). Angum gum is a natural gum exudate from mountain almond trees (Amygdalus scoparia Spach). Covalent linkage of β-lactoglobulin-Angum gum conjugate was confirmed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Emulsifying properties of emulsions containing β-lactoglobulin:Angum gum (1:1) conjugates were studied with the advancement of Maillard reaction. Dry-heating time showed no significant (p > 0.05) effect on the emulsion activity index; however, emulsion stability index were significantly increased over time and emulsion stability index of two weeks incubated β-lactoglobulin-Angum gum conjugate was significantly different (p < 0.05) from others (β-lactoglobulin-Angum gum mixture, 0, 2, 6 days, and 2 weeks). Moreover, the creaming index decreased with advancement of Maillard-type conjugation of β-lactoglobulin:Angum gum (1:1). β-lactoglobulin-Angum gum conjugates (1:1, 1:2, and 2:1) exhibited much better emulsification performance than Angum gum and gum Arabic alone at the same emulsifier/oil ratio (1.5 wt. % total biopolymer/ 40% v/v oil). In addition, assessing droplet size distribution during storage and freeze-thaw treatment revealed that β-lactoglobulin:Angum gum (1:1) conjugate had finer droplet size compared to other β-lactoglobulin/Angum gum mixing ratios (1:2 and 2:1), Angum gum and gum Arabic.     

Characterisation and optimisation of physical and oxidative stability of structured lipid-based infant formula emulsion: Effects of emulsifiers and biopolymer thickeners

Response surface methodology (RSM) was applied to investigate the effects of lecithin (0–0.4 g/100 ml), monoacylglycerol (0–0.4 g/100 ml), locust bean gum (LBG; 0–0.1 g/100 ml), and carrageenan (0–0.02 g/100 ml) on the physical and oxidative properties of structured lipid-based infant formula emulsion containing dairy proteins, lactose, vitamins, minerals and other micronutrients. Particle size, optical stability, viscosity, relative content of docosahexaenoic acid, stearidonic acid and total oxidation value were assessed during 28-day storage. ANOVA results showed that the experimental data were satisfactorily fitted to second-order polynomial models by multiple linear regression. The contour plots illustrated that lecithin and monoacylglycerol played a dominant role in controlling the emulsion stability compared to LBG and carrageenan. Lecithin content significantly affected all the responses measured, particularly lipid oxidation. Increasing monoacylglycerol concentration led to an increase in particle size and emulsion viscosity. The optimal condition to achieve the highest stability was predicted to be 0.2, 0.4, 0.045, and 0.015 g/100 ml lecithin, monoacylglycerol, LBG and carrageenan, respectively. The verification data further demonstrated the suitability of the models explored by RSM. Overall, the findings obtained in this study have important implications for the successful incorporation of structured lipid into infant formula emulsion for better infant nutrition and health.     

Influence of emulsion composition and inlet air temperature on the microencapsulation of flaxseed oil by spray drying

The objective of this work was to study the influence of some process conditions on the microencapsulation of flaxseed oil by spray drying. The process was carried out on a mini spray dryer and gum Arabic was used as wall material. Seventeen tests were made, according to a central composite design. Independent variables were: inlet air temperature (138-202 °C), total solid content (10-30% w/w) and oil concentration with respect to total solids (10-30% w/w). Encapsulation efficiency, lipid oxidation and powder bulk density were analyzed as responses. Powder morphology and particle size distribution were also analyzed. The feed emulsions were characterized with respect to droplet size and viscosity. Higher solid content and lower oil concentration led to higher encapsulation efficiency and lower lipid oxidation, which was related to the higher emulsion viscosity and lower droplets size. Increasing drying temperature resulted in higher lipid oxidation. Bulk density increased when higher solid content and lower inlet air temperature were used. The particles were rounded and shriveled, and their mean diameter was mainly affected by total solid content.     

Production of fine emulsions at pilot scale for oil compounds encapsulation

Feasibility of producing, at pilot scale (5 kg), stable oil in water emulsions with size of 1–2 μm and 100–200 nm was investigated in relation with the oil content of the emulsion (4%, 8% and 12% w/w) and with the composition of the aqueous phase.     

Freeze-thaw stability of oil-in-water emulsions prepared with native and thermally-denatured soybean isolates

Freeze-thaw stability of oil-in-water emulsions prepared with native or thermally-denatured soy isolates (NSI and DSI, respectively) as the sole emulsifier and sunflower oil (? = 0.25) has been examined at various protein concentrations (0.5, 1.0 and 2.0% w/v), comparatively with sodium caseinate (SC). The freeze-thaw stability was assessed by measurements of particle size, oiling off and gravitational separation after isothermal storage at −20 °C for 24 h and further thawing. The oil phase remained in liquid state and the amount of ice formed was similar (>97%) whatever the sample type and protein concentration. At 0.5%, NSI and DSI emulsions where highly unstable, exhibiting a coagulated cream layer with appreciable oiling off (>25%), whereas those prepared with SC were more stable, due to their initial lower flocculation degree (FD %) and particle size. For all emulsions, the increase of protein concentration (0.5–2.0% w/v) improves the freeze-thaw stability as a consequence of a decrease of initial FD %. At 2.0%, where is enough protein to cover the interface, a lower coalescence stability of NSI emulsion respect to those prepared with NSI was observed after freeze-thawing. This result can be attributed to the high tendency to aggregation of native soy globulins at subzero temperatures. Notwithstanding this, unlike the SC emulsions, the formation of new flocs in soy isolates-stabilized emulsions during freeze-thawing cannot be totally controlled.     

丁香油乳状液的制备

对影响乳状液稳定性的因素如乳化剂种类、乳化剂浓度、阿拉伯胶浓度、混合温度及混合时间等进行了研究。试验结果表明 ,香料乳状液稳定的优化条件是 :吐温 - 80用量 0 .8%、阿拉伯胶用量9.0 %、室温下混合搅拌 7min。     

Optimisation of lipase-catalysed interesterification reaction for modulating rheological and heat transfer properties of frying oil

The present work reports the optimisation of enzyme interesterification reaction of rice bran oil (RBO) and refined, bleached, deodorized, palm olein (RBDPO) blend using immobilized 1,3-specific lipase, to improve the kinematic viscosity and heat transfer coefficient of oil, important for characterising heat transfer during the frying process. Four variables, namely RBO (20–80%) in RBO–RBDPO blend, reaction temperature (25–65 °C), enzyme concentration (1–13%, w/w) and reaction time (1–13 h) were selected and optimised using response surface methodology (RSM) coupled with central composite rotatable design (CCRD). The optimisation results predicted that optimum reaction conditions for preparing enzyme interesterified oil, having minimum kinematic viscosity (2.63 × 10⁻⁶ m² s⁻¹) and maximum heat transfer coefficient (262.0 Wm⁻² °C⁻¹) were at 62% RBO, temperature 65 °C, enzyme concentration 10% (w/w) and time 6.4 h. The predicted values were validated experimentally and corroborated with DSC melting profile and triacylglycerol molecular species data. This investigation could help snack food industries to develop suitable oils for frying operations.     

粒径分析法研究原花青素乳状液的制备工艺

为了制备原花青素乳状液,采用动态超高压微射流技术处理乳状液,选取阿拉伯胶和β-环糊精作为壁材,以壁材中阿拉伯胶含量、总固形物含量、处理压力为影响因素,粒径为指标进行研究。在单因素的实验基础上,通过响应面优化分析可知最佳优化工艺为:阿拉伯胶含量为40%、总固形物含量为15%、处理压力为160 MPa。该条件下获得的乳状液的粒径预测值为629.20 nm,而粒径的真实值为633.70 nm,预测值与实际测量值吻合度为98.90%,响应值的实验值与回归方程预测值吻合良好。结论:在此条件下获得的原花青素乳状液稳定性强,分布均匀;同时根据处理压力对乳状液粒径及其分布的影响结果可知,超高压微射流可以提高乳状液的稳定性。      

Influence of main emulsion components on the physical properties of corn oil in water emulsion: Effect of oil volume fraction,whey protein concentrate and Lepidium perfoliatum seed gum

The effect of composition (whey protein concentrate, Lepidium perfoliatum seed gum, and oil content) of corn oil-in-water emulsions on their physical properties, droplet size and viscosity was studied using response surface methodology (RSM). For each response, a second-order polynomial model was developed using multiple linear regression analysis. The results indicated that the response surface models were significantly fitted for all response variables studied. It was shown that all emulsion components greatly influenced the physical properties of emulsion and its overall stability during storage. The main effect of L. perfoliatum seed gum was observed to be significant in most of response surface models. Therefore, the concentration of this gum should be considered as a critical variable for the formulation of emulsions. The overall optimum region resulted in a desirable emulsion was predicted to be obtained by combined level of 0.59% L. perfoliatum seed gum, 6% WPC and 21.95% oil volume fraction.     

OPTIMIZATION OF EMULSIFICATION AND MICROENCAPSULATION OF EVENING PRIMROSE OIL AND ITS OXIDATIVE STABILITY DURING STORAGE BY RESPONSE SURFACE METHODOLOGY

ABSTRACT

Microencapsulation is a technique by which small droplets of liquid or solid particles are coated with a thin film of wall materials to protect susceptible ingredients in food products to assure their quality or effectiveness. Microencapsulation of liquid lipid into powdery matrixes of wall materials includes two unit operations: emulsification of the lipid with an aqueous solution of wall material and drying of the emulsion. The effects of hydrophile–lipophile balance (HLB) value, emulsifier content and oil content on the evening primrose oil‐in‐water emulsion stability were studied by response surface methodology (RSM). The HLB value, emulsifier content and oil content all had significant effects on the emulsion stability (P < 0.05). Of them, the HLB value and emulsifier content contributed more effects than the oil content. The optimized HLB value, emulsifier content and oil content were used to mix with wall materials: gum arabic (GA), maltodextrin (MD) and/or sodium caseinate (NaC). The oil was encapsulated with these materials individually or in combination by spray‐drying, and their oxidative stability during storage was compared. The microcapsules with a single wall material were relatively susceptible to oxidation than those with multiple wall materials. The most desirable composition of the mixture of GA, MD and NaC by RSM was 17.2, 75 and 7.8%, respectively.

PRACTICAL APPLICATIONS

Response surface methodology (RSM) provided a valuable means to help us understand the relative or interactive effects of three important parameters: HLB value, emulsifier content and oil content on the emulsion stability of the oil‐in‐water (o/w) system. The information obtained would be useful for the preparation of similar o/w emulsion system as needed in some product development for foods. In addition, the effects of gum arabic, maltodextrin and sodium caseinate on the oxidative stability of microencapsulated oil were also studied by RSM. The results revealed the relative or interactive effects of these materials and gave the optimal conditions in minimizing the oxidative instability in this study. Since these wall materials are readily available and widely used in a variety of products, the information provided by this study would be useful for product‐developing professionals to use these materials more efficiently in terms of obtaining optimal microencapsulated products against lipid oxidation and cost effectiveness.