Peanut Oil Extraction Research Articles

Destabilization of Emulsion Formed During Aqueous Extraction of Peanut Oil: Synergistic Effect of Tween 20 and pH

AbstractTo destabilize the emulsion formed during aqueous extraction processing (AEP) of peanuts, Tween and Span series surfactants (Tween 20, Tween 80, Span 20, and Span 80) were used alone or in combination to break the emulsion. Results indicate that only Tween surfactants had a pronounced demulsifying effect that was dependent on Tween concentration and system pH. When 1.2 wt% Tween 20 aqueous solution was used for oil extraction at pH 10.0, the highest free oil yield was achieved at 76.1 %, which was similar to the oil recovery of using proteases as a destabilization agent. The results obtained using a model emulsion system containing peanut oil and Tween 20/peanut protein isolates (PPI) showed that when Tween 20 and PPI coexisted in extraction medium at pH 10.0, the dynamic interfacial tension and droplet size distribution curves were very similar to those when Tween 20 was used alone, suggesting that Tween 20 dominated at the interface, instead of PPI. Destabilization of the model emulsions relied on three important factors: inclusion of Tween 20 at the initial mixing stage, high pH, and a gentle mixing speed. A synergistic destabilization mechanism of using Tween 20 at high pH during AEP was proposed. The discovery of Tween 20 as an effective demulsifier significantly contributes to the development of AEP of oilseeds.

Assessment of Taste Attributes of Peanut Meal Enzymatic-Hydrolysis Hydrolysates Using an Electronic Tongue

Peanut meal is the byproduct of high-temperature peanut oil extraction; it is mainly composed of proteins, which have complex tastes after enzymatic hydrolysis to free amino acids and small peptides. The enzymatic hydrolysis method was adopted by using two compound proteases of trypsin and flavorzyme to hydrolyze peanut meal aiming to provide a flavor base. Hence, it is necessary to assess the taste attributes and assign definite taste scores of peanut meal double enzymatic hydrolysis hydrolysates (DEH). Conventionally, sensory analysis is used to assess taste intensity in DEH. However, it has disadvantages because it is expensive and laborious. Hence, in this study, both taste attributes and taste scores of peanut meal DEH were evaluated using an electronic tongue. In this regard, the response characteristics of the electronic tongue to the DEH samples and standard five taste samples were researched to qualitatively assess the taste attributes using PCA and DFA. PLS and RBF neural network (RBFNN) quantitative prediction models were employed to compare predictive abilities and to correlate results obtained from the electronic tongue and sensory analysis, respectively. The results showed that all prediction models had good correlations between the predicted scores from electronic tongue and those obtained from sensory analysis. The PLS and RBFNN prediction models constructed using the voltage response values from the sensors exhibited higher correlation and prediction ability than that of principal components. As compared with the taste performance by PLS model, that of RBFNN models was better. This study exhibits potential advantages and a concise objective taste assessment tool using the electronic tongue in the assessment of DEH taste attributes in the food industry.

Incorporation of Groundnut Meal in Selected Products after Removal of Aflatoxin

KEYWORDS Aflatoxin. Groundnut Meal. Malnutrition. Novel Protein Source. Value Addition ABSTRACT Groundnut meal is the high protein by-product remaining after commercial extraction of peanut oil. Groundnut meal applications are limited because of typical high concentrations of aflatoxin. In the present study technology was developed to prepare protein rich powder from an oil extracted groundnut. To make the meal free from aflatoxin four treatments were employed viz. ether treatment, heat treatment, acid-alkali treatment and homestead acid-alkali treatment. After each treatment, the powder was subjected to analysis of protein and aflatoxin and acceptability for sensory characteristics. A reduction ranged from 17.86 to 100 percent of aflatoxin and 29.17 to 70.47 percent of protein. A comparative evaluation of four powders indicated that homestead acid alkali treatment is free from aflatoxin and containing 10.09gm of protein. This powder was incorporated in three products, that is, batti, besan laddu, and sweet biscuits at 35 and 50 percent level. Acceptability was assessed on 9 point hedonic rating scale. The mean overall acceptability of reference, 35 percent and 50 percent incorporated batti were 8.1, 7.2 and 6.3, besan laddu 8.0, 7.3 and 6.8 sweet biscuits 7.6, 7.4 and 6.5 respectively, revealing that the developed powder is acceptable at moderate level in various products. No significant difference (P>0.05) was found between reference and 35 percent incorporated product and between 35 and 50 percent incorporated products. However, the 50 percent incorporated product scored significantly lower than the reference, specifically for colour and appearance. The study concluded that aflatoxin can be removed from groundnut meal and further, can be used in different recipes as protein source.

Assessment of cadmium bioaccumulation and distribution in the kernels of peanut widely cultivated in China

To determine the low Cd accumulation genotypes of peanut and the key factor contributing to high Cd accumulation in peanut kernels, cadmium (Cd) bioaccumulation and distribution in the kernels of nineteen genotypes of peanut widely cultivated in China were estimated in field experiment during duration of 130 days. Results showed that only four genotypes (Yuhua9626, Jihua9606, Luhua11 and Quanhua646) were identified as low-Cd accumulation group according to hierarchical cluster analysis. Cd accumulated in the nutritional tissues of the kernels followed in the order: extracted protein>residues>peanut oil. The protein plays a key role in the abnormal accumulation of Cd in the kernels of peanut. Thus, the control of human ingestion risk can be done by the extraction of peanut oil during deep processing of peanut. Meanwhile, the protein and residues of peanut should be paid more public attention when they enter into the food chain.

Optimization of the protein concentration process from residual peanut oil-cake

The objective of this study was to find the best process conditions for preparing protein concentrate from residual peanut oil-cake (POC). The study was carried out on POC from industrial peanut oil extraction. Different protein extraction and precipitation conditions were used: water/ flour ratio (10:1, 20:1 and 30:1), pH (8, 9 and 10), NaCl concentration (0 and 0.5 M), extraction time (30, 60 and 120 min), temperature (25, 40 and 60 °C), extraction stages (1, 2 and 3), and precipitation pH (4, 4.5 and 5). The extraction and precipitation conditions which showed the highest protein yield were 10:1 water/flour ratio, extraction at pH 9, no NaCl, 2 extraction stages of 30 min at 40 °C and precipitation at pH 4.5. Under these conditions, the peanut protein concentrate (PC) contained 86.22% protein, while the initial POC had 38.04% . POC is an alternative source of protein that can be used for human consumption or animal nutrition. Therefore, it adds value to an industry residue.

Development of a pilot-scale process to sequester aflatoxin and release bioactive peptides from highly contaminated peanut meal

Peanut meal (PM) is the high protein by-product remaining after commercial extraction of peanut oil. PM applications are limited because of typical high concentrations of aflatoxin. For the first time, pilot-scale extraction of protein and sequestration of aflatoxin from PM were evaluated. Aqueous PM dispersions were mixed with two commercial bentonite clays and Alcalase in a jacketed mixer, hydrolysed for 1 h, heated to inactivate protease, and solids and liquids were separated using a decanter. Liquid hydrolysates derived from this process had >90% reduction in aflatoxin when clay was present. ACE-inhibitory activities of these hydrolysates suggest a potential benefit for blood pressure regulation. The insoluble fractions from the dispersions were dried and used in a separate turkey poult feeding study. These results indicate that scale-up of this novel process is feasible and offers a means for adding value to this underutilized protein source.

Biodiesel production via peanut oil extraction using diesel-based reverse-micellar microemulsions

Vegetable oils have been studied as a feasible substitute for diesel fuel, and short term tests using neat vegetable oils have shown results comparable to those of diesel fuel. However, engine problems arise due to the high oil viscosity after long-term usage. Vegetable oil/diesel blending as biodiesel fuel has been shown to be one technique to reduce vegetable oil viscosity. The goal of this research is to demonstrate the feasibility of producing this biodiesel fuel via vegetable oil extraction using diesel-based reverse-micellar microemulsions as an extraction solvent. In this extraction technique, peanut oil is directly extracted into the oil phase of the microemulsion based on the “likes dissolve likes” principle and the product of the extraction process is peanut oil/diesel blend. The results show that diesel-based reverse micellar extract oil from peanuts more effectively than both diesel and hexane alone under the same extraction condition. An extraction efficiency of 95% was achieved at room temperature and short extraction time of 10 min in just a single extraction step. The extracted peanut oil/diesel blend was tested for peanut oil fraction, viscosity, cloud point and pour point, which all meet the requirements for biodiesel fuel.

Aqueous enzymatic extraction of peanut oil and protein hydrolysates

The aqueous enzymatic process of simultaneously preparing oil and protein hydrolysates from peanut was investigated. The optimum parameters for hydrolysis using Alcalase 2.4L were established by the single-factor and orthogonal test. The optimal processing conditions were as follows: hydrolysis temperature 60 °C, pH 9.5, ratio of material to water 1:5 (w/w), alkaline extraction time 90 min, enzyme amount 1.5% (w/w) and hydrolysis time 5 h. Under these conditions, the free oil and protein hydrolysates yields were 79.32% and 71.38% respectively. In order to improve these yields, As1398 was chosen to hydrolyze the residue and emulsion. The total free oil and protein hydrolysates yields were increased to 91.98% and 88.21% respectively.

Study on the Effects of Enzymatic Hydrolysis on the Physical, Functional and Chemical Properties of Peanut Protein Isolates Extracted from Defatted Heat Pressed Peanut Meal Flour (Arachis hypogaea L.)

Physical, chemical and functional properties of peanut protein isolates (HPI) and hydrolysis (HPH) extracted from peanut meal obtained from heat treated peanut oil extraction method were analyzed. HPH exhibited superior functional properties such as whipping, emulsification, fat and water absorption properties. Thermal denaturation profiles indicate that there is no significant difference (p<0.05) between HPI and HPH at both onset and transition temperatures. However, the conclusion temperatures were found to be significantly different (p<0.05). Protein solubility was pH dependent with HPH been more soluble at all pH levels. However, solubility was low at the isoelectric pH range of 4.5-5.5. Electrophoretic patterns obtained from SDS-PAGE show that HPH registered a lower molecular weight (<31KDa) compared to HPI ( 66 KDa). HPH had relatively smaller particle sizes (±0.1 µm) compared to HPI (±100 µm). Protein isolates extracted from peanut meal obtained from cold pressed peanut oil extraction method were used as control in analyzing functional parameters but HPH still exhibited superior qualities. Both HPH and HPI were found to b e nutritionally rich in most essential amino acids with respect to the recommended FAO/WHO amino acid requirement patterns for both adults and children.

SOME RHEOLOGICAL PROPERTIES OF AQUEOUS PEANUT FLOUR DISPERSIONS*

ABSTRACT The rheological behaviors of aqueous peanut flour dispersions were characterized across a range of conditions, including controlled heating and cooling rates under both large‐ and small‐strain deformations. Fat content of the dry flours influenced rheological changes, as dispersions of higher‐fat flours were less viscous than lower‐fat flours on an equal weight basis. A roast effect was also apparent, especially for dispersions of the higher‐fat flours in which light roast flours were more viscous than dark roast flours. Dispersions of toasted soy flour were more viscous at lower temperatures (&lt;75C), but at higher temperatures, low‐fat peanut flour dispersions were more viscous than soy. Centrifugal separation revealed that the insoluble material of all dispersions primarily contributed to the observed rheological responses. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis was used to characterize the soluble and insoluble proteins making up the various dispersions, and these results are discussed in terms of observed rheological phenomena.PRACTICAL APPLICATIONSPeanut flour is a dry powder prepared after partial extraction of peanut oil from roasted peanut seed. This flour, as compared to peanut butter or whole peanut seed, has numerous functional advantages in formulated foods, including improved stability to lipid oxidation, an enriched protein content and the handling ease of a powder. However, there is no published fundamental rheological data pertaining to these ingredients. Accordingly, commercially available peanut flours with varying roast intensities and fat contents were rheologically characterized in aqueous dispersions, both in the absence and presence of heat. Residual fat content in the flours primarily affected rheological behaviors, with high‐fat flours being less viscous under equivalent conditions. A yield stress was observed in all dispersions held at 40C, which correlated with stability of the dispersion to particle settling. This data could ultimately aid texture optimization of products containing such flours.

Enzyme‐assisted aqueous extraction of peanut oil

AbstractEnzyme‐assisted aqueous extraction of oil from oilseeds is a relatively recent technique. In the present study, peanut oil was extracted under optimized aqueous extraction conditions using Protizyme™, which is predominantly a mixture of acid, neutral, and alkaline proteases. The optimal conditions were: enzyme concentration of 2.5% (w/w) in 10 g of peanut seeds, pH 4.0, 40°C, and 18 h incubation with constant shaking at 80 rpm. Centrifuging the mixture at 18,000 × g for 20 min separated the oil with a recovery of 86–92%. The merits of this process over existing solvent extraction and/or mechanical pressing methods are discussed.

Modeling of Liquid CO2 Extraction of Peanut Oil in a Fixed Bed

ABSTRACT BATCH extraction of peanut oil with liquid carbon dioxide in a fixed bed is described with several models. Equations to describe oil extraction kinetics are presented. In addition to being dependent on temperature and pressure, the extraction rate curves are shown to be dependent on oilseed particle size. The oil concentration gradient in the bed is fitted to a solid/liquid chromatographic column model. The minimum length of bed needed to keep a continuous system operating at its optimum rate is estimated by the method of a breakthrough curve.

Peanut oil extraction using compressed CO 2

Supercritical carbon dioxide (SCCO 2) extraction of oil from peanuts is an alternative to hexane extraction or the mechanical oil press. Oil was successfully extracted using SCCO 2 at temperatures of 25–120°C and pressures of 140–690 bar. Pressure, temperature, and extraction vessel orientation affected the extraction of oil. In the range studied, the highest values of temperature and pressure gave the highest extraction rates. Above about 400 bar, increasing the temperature significantly improved the extraction rate, while below 400 bar increasing the temperature reduced the rate. Decreasing the particle size increased the extraction rate and the total oil recovered.

Peanut Oil Extraction with SC-CO2: Solubility and Kinetic Functions

ABSTRACT VARIOUS factors affecting SC-CO2 peanut oil extraction were examined. Pressure, temperature, particle size, moisture, and flow rate effects in a vertical extractor were evaluated using a half-factorial design. The effect of temperature and pressure was studied further for temperatures of 25 to 95C and pressures of 140 to 550 bar. At 25C and 550 bar, the particle size dependence of both the initial extraction rate and the overall oil yield was studied for particle size of 0.864 to 4.75 mm.

3H-reserpine persistently bound “in vivo” to rat brain subcellular components: Limited removal by peanut oil extraction

Removal by peanut oil extraction was used to study the binding of the highly liposoluble drug reserpine to rat brain subcellular components. When 3H-reserpine was added to the brain “in vitro” or administered to the animals 1 hr before, the binding was “labile” and most of the drug was removed by peanut oil extraction. In the brain of the animals treated with reserpine 24 hr before, the drug was “persistently” bound to the mitochondrial and microsomal fractions and its removal by peanut oil was comparably reduced.