Enzyme‐assisted aqueous extraction of safflower oil: optimisation by response surface methodology

Aqueous enzymatic oil extraction of safflower seeds was assisted by Alcalase 2.5L and Celluclast 1.5L. Enzyme type and amount, pH, time, temperature, churning rate, dilution ratios and particle size were varied to determine their influence on the oil amount. The amount of oil recovered was higher using seeds ground to a particle size of <0.6 mm. Response surface methodology was employed for the optimisation of aqueous enzymatic oil extraction conducted with Celluclast 1.5L. When the extraction was assisted by Celluclast 1.5L, the maximum oil amount and yield were 33.3 (% w/w) and 79.7 (% w/w), respectively. The optimum conditions were 48.3 °C; 0.25 mL enzyme g^?1 substance; pH, 4.84; resulting oil amount and yield were 28.2 (% w/w) 65 (% w/w), respectively. The predicted critical values were experimentally verified, and an oil amount of 27.1 (% w/w) was achieved. The enzyme treatment did not have any determining effect on the physicochemical properties of extracted oil.     

Effect of commercial enzymatic preparation with pectolytic activities on conventional extraction and ultrasound‐assisted extraction of oil from grape seed (Vitis vinifera L.)

Conventional solvent extraction (CE) and ultrasound‐assisted extraction (UAE) in hexane for oil from untreated and enzyme‐treated grape seeds were investigated and compared. Among the output power tested (50, 100 and 150 W) in UAE on untreated seeds, UAE at 150 W for 30 min with liquid‐to‐solid ratio 8:1 (v/w) gave oil extraction yield comparable to CE (ca. 14% w/w) for 6 h with liquid‐to‐solid ratio 12:1 (v/w). CE and UAE at 150 W did not influence the fatty acid profiles of oil. CE oil was found to be the most oxidised. The enzymatic treatments (2, 4 and 6 g per 100 g seeds of Rapidase^® Expression) prior to CE enhanced by 2.5% of the oil yield. Enzymatic treatments higher than 2 g per 100 g seeds increased relative value of some fatty acids both in CE and UAE. Enzymatic pretreatment from 2 to 4 g per 100 g seeds significantly improved some physicochemical parameters of oil quality when extracted by CE, but not by UAE.     

Optimization of the enzymatic treatment during aqueous oil extraction from sunflower seeds

Partially dehulled sunflower seeds were subjected to a hydrolytic treatment with cellulases during aqueous processing for oil and protein extraction. Sub-optimal extraction conditions (particle size and separation technology) were established in order to appreciate the potential improvement caused by the enzymatic treatment and to select the best operational conditions. The effects of three operational variables (extraction–treatment time, water/seeds ratio and enzyme/seed ratio) were studied on three objective functions (the extent of hydrolysis reaction, the oil extraction yield and the percent polyphenolics removal). After 2 h of enzymatic treatment–extraction a practical optimum in the range 7.5–8 g water g⁻¹ seeds and 1.25–1.4 g enzyme 100 g⁻¹ seeds could be defined. Under these conditions the oil extractability and the polyphenolics removal are improved by more than 30 and 80%, respectively.     

Optimising conditions for enzymatic extraction of edible gelatin from the cattle bones using response surface methodology

This work was initiated to optimise the factors affecting the enzymatic extraction of edible gelatin from the cattle bones using response surface methodology. A central composite rotatable design was used to evaluate the effects of the enzyme concentration, time of enzymatic treatment and extraction temperature on the yield of extraction, gel strength, apparent viscosity and absorption at 420 nm. The R ² values of regression models for all the response variables were higher than 0.9. Data analysis showed that all the process variables significantly ( P  < 0.01) affected the gel strength and apparent viscosity of extracted gelatin, whereas the effect of extraction temperature on both yield of extraction and absorption at 420 nm was not significant ( P  > 0.05). Graphical optimum conditions for the extraction yield, gel strength, apparent viscosity and absorption at 420 nm were determined as 6.1 ppm, 15.6 h, 70 °C; 9.1 ppm, 11.9 h, 70.3 °C; 7.86 ppm, 14.9 h, 77.5 °C and 2.8 ppm, 10 h, 60 °C, respectively. For all the response variables, the experimental values were very close to the predicted values and were not statistically different ( P  < 0.05).     

Oil extractability from enzymatically treated goldenberry (Physalis peruviana L.) pomace: range of operational variables

Goldenberry pomace (seeds and skins) represents a large portion of the waste generated during juice processing (ca. 27.4% of fruit weight). The potential of goldenberry agro‐industrial wastes for use as raw material for production of edible oil was evaluated. Fruit pomace, contained 6.6% moisture, 17.8% protein, 3.10% ash, 28.7% crude fibre and 24.5% carbohydrates. The n‐hexane‐extractable oil content of the raw by‐products was estimated to be 19.3%. Aqueous enzymatic extraction was investigated for recovery of oil from the fruit pomace. The most significant factors affecting extraction were enzyme concentration, the time of digestion with enzymes, substrate concentration in water and the particle size of substrate. A broad variation in oil recovery was obtained depending on the operational conditions during the enzyme‐aided aqueous extraction. The optimum and economical values were those obtained for 4:0.02:1 water:enzyme:substrate ratio. Generally, enzymatic treatment increased the extraction yield. The more than 42% yield by enzymation compared with the nearly 3% yield in the control process (without enzyme) implies a significant increase in yield by about 92.8%. In single‐enzyme trials, cellulase EC gave the best yield. Although proteases slightly improve yield, the enhancement values are much lower than those obtained with Cellulase EC and Pektinace L40. Rapid increase in oil yield occurred as the enzyme concentration increased from 1 to 2 g/100 g substrate. Yield increased with dilution, but it began to fall when the substrate became more diluted. Moreover, extractability increased significantly when particle size reduced. Concerning the oil composition, there were no great changes in the fatty acid pattern of the oils extracted with different hydrolytic enzymes when compared with each other or to the solvent extracted oil. The main purpose of this study was to maximise the efficiency of the enzymatic treatment for oil recovery from goldenberry pomace. As a first step toward developing goldenberry as a commercial crop, the results provide important information for the industrial application of the fruit.     

AQUEOUS EXTRACTION OF OIL AND PROTEIN FROM SOYBEAN AND LUPIN: A COMPARATIVE STUDY

This study compares the effects of extrusion pretreatment and protease addition during aqueous extraction processing (AEP) of soybean and lupin flakes. AEP of flakes resulted in the lowest yields of oil (56%), protein (71%) and [cream  +  free oil] (8%) for soybean, while for lupin, yields were 48, 69 and 2%, respectively. AEP protein extraction yields were decreased by extrusion pretreatment, but this pretreatment improved enzymatic action, increasing protein extractability from soybean and lupin by 47 and 26%, respectively. For both protein crops, enzyme-assisted AEP (EAEP) of extruded flakes yielded the highest oil, protein and [cream  +  free oil] yields, which were 96, 85 21%, respectively, for soybean. Yields for lupin were 81, 77 and 10%, respectively. Extrusion followed by enzyme addition positively impacted demulsification yield, the creams from EAEP of soybean and lupin extruded flakes being the less stable toward enzymatic demulsification .

PRACTICAL APPLICATIONS

The vegetable oil industry is looking for alternatives to the traditional solvent extraction of oil-bearing seeds, and there is a need to increase the inefficient conventional aqueous extraction of protein from residual defatted meal, a by-product of the oil extraction process. The concept of enzyme-assisted aqueous extraction processing (EAEP) has been successfully developed for extruded soybean material, but its efficiency on other oil-bearing seeds still needs to be demonstrated. By determining the oil and protein extraction yields recovered during EAEP of extruded lupin flakes, the feasibility of transferring this process from soybean to other oilseeds will be established.     

响应面法优化酶法提取麻疯树籽油工艺研究

该文报道酶法提取麻疯树籽油工艺,在单因素试验基础上,利用Box–Benhnken中心组合试验和响应面分析法(RSM),对影响麻疯树籽出油率关键因素进行优化探讨。结果表明,纤维素酶具有较好酶解能力,最佳工艺条件为:加酶量2.1%、酶解温度43℃、料液比1∶5(g/mL)、酶解时间3 h,麻疯树籽油得率可达80.71%,较无酶条件下得率提高20%。     

Pressing and supercritical carbon dioxide extraction of walnut oil

The objective of this study was to evaluate the oil extraction process from walnut seeds by pressing followed by extraction with supercritical CO₂. In pressing experiments, a factorial arrangement was conducted in order to study the combined effects of seed moisture content (2.5%, 4.5% and 7.5%) and pressing temperature (25, 50 and 70 °C) on oil recovery and quality parameters. For all conditions tested, the oil quality compared well with that of cold-pressed walnut oil. Oil recovery increased significantly as moisture content raised. Highest oil recovery (89.3%) was obtained at 7.5% moisture content and 50 °C temperature. The cake resulting from pressing at these conditions was extracted with CO₂ in a high pressure pilot plant with single stage separation and solvent recycle. The effects of two different pressures (200 and 400 bar) and temperatures (50 and 70 °C) with regard to oil yield and quality, and time required for extraction were analyzed. At each condition, the extraction rate changed with the mass of solvent and extraction time. At first, the mass of oil extracted was determined by the oil solubility in CO₂ and a linear relationship was observed, where the slope results in the solubility of oil in CO₂ at the experiment conditions. After that, the extraction rate was governed by solubility and diffusion, and continuously decreased with time. The colour changed along the extraction from a whitish clear product to a yellow one. Tocopherol and carotenoid contents were significantly higher than those obtained by pressing. Extraction conditions did not affect significantly the fatty acid composition.     

Extraction and fractionation of lipolytic enzyme from viscera of Monterey sardine (Sardinops sagax caerulea)

In this study, lipolytic activity of a semi-purified lipolytic enzyme (SLE) from the viscera of sardine ( Sardinops sagax caerulea ) was screened on the lipolysis of olive, Menhaden and sardine oil. A lipolytic enzyme was partially purified from the crude extract of sardine viscera by fractional precipitation followed by ultrafiltration (30 kDa). The main tissues found in sardine viscera were pyloric caeca (19.0% w/w), digestive tract (13.0% w/w), liver (4.8% w/w) and pancreas (1.5% w/w). Results show that pancreas had the highest lipolytic activity. There were no significant differences in lipolytic activity between pyloric caeca, intestine and liver ( P  < 0.05). Specific activity of the SLE increased 47.0-fold after extraction and fractionation, with a yield of 0.34% calculated for the whole viscera weight. Lipolytic activity of SLE from sardine viscera increased threefold when sardine oil was used as substrate. The results of this study confirm the potential importance of lipases from marine sources.     

真菌发酵预处理麻疯树籽高效提油初步研究

利用真菌固液态发酵麻疯树籽,通过测定还原糖和氨态氮含量变化,判断真菌对营养成份利用情况与油脂提取效果关系。实验结果表明,经黑曲霉固液态发酵预处理麻疯树籽在发酵48 h得到最大提油量,分别为32.75%(w/w)和31.95%(w/w),比对照组(27.5%,w/w)分别提高19.1%和16.2%;补充适量葡萄糖后有利于提高提油量,经黑曲霉固液态发酵预处理麻疯树籽都在发酵72 h后达最大提油量,分别为35.75%(w/w)和34.65%(w/w),比对照组(27.5%,w/w)分别提高30%和26%。经实验,黄曲霉不适于麻疯树籽发酵,发酵后提油效果没明显提高。     

EFFECT OF ENZYMATIC TREATMENT OF CORN GLUTEN MEAL ON LUTEIN, ZEAXANTHIN AND β-CRYTOXANTHIN EXTRACTION

Response surface methodology was used to optimize some operating parameters on the effects of alcalase treatment extraction of lutein, zeaxanthin and β -cryptoxanthin from corn gluten meal (CGM) on the yield of total xanthophylls. Three independent variables tested were enzyme concentration, substrate concentration and hydrolyzing time. The t -test and P value indicated that the quadratic of the three variables, enzyme concentration and hydrolyzing time were important linear variables affecting the total xanthophyll yield ( P <  0.005), followed by substrate concentration ( P <  0.01). The interaction effect between enzyme concentration and hydrolyzing time was also significant ( P <  0.005). Considering the efficiency, the economy of materials and the feasibility of experiment, the technique parameters were optimized by constrained complex method. The optimum conditions were obtained as follows: the enzyme concentration, the substrate concentration and the hydrolyzing time were 4,367 U/g, 11.3% and 2.4 h, respectively. The highest total xanthophyll yield was predicted of 65.69  µ g/g when CGM was hydrolyzed under the optimum condition. The suitability of the model equation for predicting the optimal response values was tested using the selected optimum conditions; the experimental yield was 65.06  ±  0.78  µ g/g, which was found to be in agreement with the predicted yield.

PRACTICAL APPLICATIONS

Corn gluten meal (CGM), a major by-product of corn wet milling, contains (on a dry basis) 200–400  µ g/g carotenoids. There are ∼840,000 tons of CGM produced in China every year. If a part of CGM produced was manufactured further to produce carotenoids as foods, materials of foods and additives of pharmaceutical products, its value and presence in the marketplace would be increased.     

Response surface optimisation of aqueous enzymatic oil extraction from bayberry (Myrica rubra) kernels

Aqueous enzymatic extraction (AEE) of oil from Myrica rubra kernels was performed. The four AEE parameters namely mixed enzyme (cellulose/neutral protease = 1/2, w/w) amount, liquid/solid ratio, extraction time, and temperature, were optimised by response surface methodology. The statistical analysis indicated that the enzyme amount, liquid/solid ratio, time, and the quadratics of liquid/solid ratio, and enzyme amount, as well as the interactions between time and temperature, showed significant effects on oil yield. The optimal extraction conditions for oil yield were mixed enzyme amount, liquid/solid ratio, time, temperature as 3.17% (w/w), 4.91 ml/g, 4 h and 51.6 °C. Under the optimum conditions, the experimental oil extraction yield was 31.15%. The GC–MS analysis showed that the oil was abundant in the unsaturated fatty acids (9-octadecenoic acid and 9,12-octadecadienoic acid accounting for more than 80%), and the AEE was more efficient method to extract polyunsaturated fatty acid than the organic solvent process.     

水酶法提取火麻籽油工艺研究

以火麻籽为原料,利用水酶法提取火麻籽油。通过单因素实验及中心组合实验研究酶的种类、料液比、加酶量、酶解时间等因素对火麻籽提油率的影响。结果表明,酸性蛋白酶和纤维素酶按1∶1进行复配且先加酸性蛋白酶作为提取酶时,提取效果最好;在此基础上,通过响应面优化得到水酶法提取火麻籽油的最佳工艺条件为:复合酶添加量1.10%(w/w)、料液比1∶3.6g/mL、酶解时间3.8h,火麻籽油的提油率为75.64%。      

INTERACTION EFFECTS BETWEEN ASCORBIC ACID AND CALCIUM CHLORIDE IN MINIMIZING BROWNING OF FRESH-CUT GREEN BANANA SLICES

Dopamine level of three banana varieties was determined by spectrophotometry. Dwarf Cavendish banana had the highest browning potential and was used for processing into fresh-cut slices. The slices were treated with anti-browning agents, packed at 55% vacuum level and stored at 10C. A 2  ×  3 factorial treatment structure was used to investigate the interaction effects between ascorbic acid and calcium chloride. At three-day intervals, physico-chemical parameters were investigated. The interaction effect between ascorbic acid and calcium chloride for lightness and redness was significant ( P <  0.05); however, these color parameters were mainly driven by the main effect of ascorbic acid ( P <  0.01). The interaction effect between ascorbic acid and calcium chloride and the main effect of each chemical on firmness were highly significant ( P <  0.01). There was no interaction effect on yellowness ( P >  0.05). Browning and loss of firmness were promoted when 4% calcium chloride was used singly and minimized when 2% ascorbic acid was added.

PRACTICAL APPLICATIONS

Green bananas are widely used in many cooking dishes and utilized in the manufacture of several industrial food products like banana flour, deep-fried chips and baked banana crisps. However, one of the major limitations of green peeled bananas as a raw material, to successfully penetrate the market, is the excessive enzymatic browning after peeling. This badly affects the product's color and decreases the quality of the produce. A combination of naturally occurring substances, calcium chloride (2%) and ascorbic acid (2%) significantly minimized enzymatic browning of green peeled bananas under partial vacuum packaging, while retaining the firmness of the produce and maintaining a shelf life of 12 days at 10C.     

Optimisation study of gum extraction from Basil seeds (Ocimum basilicum L.)

Basil seed ( Ocimum basilicum L.) is cultivated in large quantities in different regions of Iran. This seed has reasonable amounts of gum with good functional properties which is comparable with commercial food hydrocolloids. A central composite rotatable design was applied to evaluate the effects of temperature, pH and water/seed ratio on the yield, apparent viscosity and protein content of water-extracted Basil seed gum. All of the variables significantly ( P  < 0.05) affected the extraction yield, whereas the effect of water/seed ratio on apparent viscosity and the effects of pH and water/seed ratio on protein content were not significant ( P  > 0.05). Numerical optimisation determined the optimum extraction conditions based on the highest yield and viscosity and the lowest protein content as being temperature 68.71 °C, pH 8.09 and water/seed ratio 65.98:1. Power law model well described non-Newtonian pseudoplastic behaviour of BSG. Flow behaviour index ( n ) and consistency index ( K ) of 1% crude and pure BSG samples were 0.306, 0.283 and 17.46, 20.22 Pa s ⁿ , respectively.     

EFFECT OF ANTEMORTEM JOURNEY AND LAIRAGE AT ABATTOIR ON RABBIT MEAT QUALITY

A study was conducted to determine the effects of journey duration (1 versus 3 h) and lairage time at abattoir (0 versus 5 h) on rabbit meat quality traits. Rabbits transported for 3 h produced meat with significantly higher pH values ( P <  0.01), darker (lower L* values, P <  0.01) and less yellow ( P <  0.05) color, as well as lower losses during cooking ( P <  0.01), than those transported for 1 h. Moreover, animals laired for 5 h yielded meat with more ( P <  0.05) yellow color, cooking losses ( P <  0.05) and higher shear values ( P <  0.01) than rabbits not laired before slaughtering. The nuclear magnetic resonance analysis revealed that these differences ( P <  0.05) are mainly related to changes occurring in the distribution of myofibrillar (T₂₁) and extra-myofibrillar (T₂₂) water. In conclusion, this study indicated that journey time and lairage at abattoir may play an important role in determining rabbit meat quality traits.

PRACTICAL APPLICATIONS

In many previous studies that considered the effect of journey and lairage on rabbit meat quality, animals were stress-induced by extreme conditions of journey and/or lairage that were unlikely to occur during commercial operations. The aim of this study is to establish whether meat quality characteristics are still influenced when journey and lairage times match current commercial production practices. Because processing-plant efficiency depends on product uniformity, it will be interesting to test the potential variability effect of rabbit preslaughter practices on meat quality properties.     

EXTRACTION OF VICTORIA AND RED GLOBE GRAPE SEED OILS USING SUPERCRITICAL CARBON DIOXIDE WITH AND WITHOUT ETHANOL

SFE of the oils of two varieties of grape seeds (Victoria and Red Globe) was performed in a flow apparatus at 40C and 250 bar. The effect of the solvent on the extraction yield was studied using CO₂ and CO₂ modified with ethanol, and the yield of extraction was compared with conventional extraction methods (Bligh and Dyer and Soxhlet using hexane). SC CO₂  +  ethanol extracted higher lipid amounts from both varieties, compared with SC CO₂ extraction. The comparison between SFE and conventional extraction methods showed that the highest extraction yield was obtained with SC CO₂  +  ethanol (10%, w/w) (14.7 and 11.8% for Red Globe and Victoria grape seeds, respectively), while pure SC CO₂ afforded the lowest lipid yields. The fatty acid compositions of the oils obtained by SFE were analyzed. Fractions containing higher proportions of PUFAs were obtained at lower solvent/dry grape seed ratios, while fractions richer in SFAs and MUFAs were obtained at higher solvent/dry grape seed ratios.

PRACTICAL APPLICATIONS

SFE could fractionate grape seed oil and afford various grades of oil containing different proportions of fatty acids. The highest grape seed lipid yield obtained was with SC CO₂ + ethanol, making this solvent a promising and powerful one for grape seed oil extraction, showing a great advantage compared with conventional extraction methods.     

响应面优化芥末籽油的水酶法提取工艺及其脂肪酸分析

以芥末籽为原料,芥末油出油率为指标,首先确定最佳使用酶为碱性蛋白酶,通过单因素试验考察酶解温度、酶解时间和料液比等因素对出油率的影响,在此基础上,再结合响应面试验优化法,建立芥末籽油水酶法提取工艺并对芥末油进行脂肪酸分析。结果表明,碱性蛋白酶对芥末籽出油率的效果最佳;当加酶量为2.5%(g/100 mL)、酶解pH10、酶解温度为45 ℃、液固比为7:1 (mL/g)和酶解时间为6 h时,芥末籽出油率达到了23%,与预测值相差1.8%。采用GC-MS分析脂肪酸组分发现,不饱和脂肪酸相对含量高达81.34%,饱和脂肪酸相对含量为12.40%,油酸总含量高达50.72%,芥酸相对含量达到16.42%,二十碳-1-烯酸相对含量达到13.51%,本研究结果可为芥末籽油的综合开发与利用提供新的途径。     

Degradation kinetics of tomato juice quality parameters by ozonation

Tomato juice samples were ozonated with control variables of ozone concentration (1.6–7.8 %w/w) and treatment time (0–10 min). Effects of ozone processing variables on quality parameters of pH, ^oBrix, titratable acidity (TA), cloud value, non-enzymatic browning, colour values ( L *, a *, and b *) and ascorbic acid (AA) content were determined. No significant changes ( P  > 0.05) in pH, ^oBrix, TA, cloud value and Non enzymatic browning (NEB) ( P  ≤ 0.05) were found with ozonation. L *, a * and b * colour values were significantly affected by ozone concentration and treatment time. A significant reduction of AA (96 %) was observed at an ozone concentration of 7.8%w/w and a treatment time of 10 min. Results presented in this study indicate that visual colour and nutritional quality is significantly affected during ozone processing. Thus, the effects of ozonation on the nutritional properties of tomato juice should be considered by processors prior to its adoption as a preservation technique.     

Effects of high-pressure treatment on the extraction yield, phenolic content and antioxidant activity of litchi (Litchi chinensis Sonn.) fruit pericarp

As a promising technique, high-pressure extraction (HPE) method was used to extract bioactive compounds from litchi fruit pricarp. The study involved in different experimental factors such as solvent, ethanol concentration (35-95, v/v), material to solvent ratio (1:25-1:100, w/v), acidic medium, extraction pressure (200-500 MPa), time (2.5-30 min) and temperature (30-90 °C). The extraction yield, total phenolic contents, 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity and superoxide anion scavenging capability of the HPE sample were examined and then compared with those of ultrasonic extraction and conventional extraction samples. The application of HPE obtained higher extraction yield compared to other extraction methods. However, there were no significant differences ( P  >   0.05) in the total phenolic content and the antioxidant activities among these various extractions. Compared with some conventional extraction method, the HPE exhibited higher extraction efficiency in terms of higher extraction yield and extraction time.