Investigation of hotpot oil based on beef tallow and flavored rapeseed oil in commercial hotpot seasoning

This study aimed to investigate the quality of hotpot oil from various hotpot seasonings. For this, 12 representative hotpot seasonings with beef tallow (BT) and flavored rapeseed oil (FRO) were collected before the hotpot oil was extracted. The oil content, sensory evaluation scores, physiochemical properties, fatty acid composition, harmful substances, and nutrient content of the hotpot oil were subsequently analyzed. The results showed that the oil content of the hotpot seasoning was 38.3%–58.2%. Furthermore, the BT hotpot oils produced better sensory scores (7–8.5), and their oxidative stability (12.08–13.17 h) was higher on average than that of the FRO hotpot oils. Additionally, the FRO hotpot oils had higher contents of unsaturated fatty acid (81.70%–97.32%), phytosterol (3466.07–6110.37 ppm), tocopherol (182.91–1276.17 mg kg⁻¹), and polyphenol (34.48–61.94 mg kg⁻¹). The factor analyses revealed that the FRO and BT hotpot oils were significantly different and were affected by the iodine value, acid value, and linoleic acid and phytosterol contents. Practical applications: It is necessary to improve the nutritional value and taste of hotpot oils to facilitate rapid development in the hotpot seasoning industry. This study showed FRO was a positive mediator of antioxidant, anti-inflammatory, and anticancer effects owing to its richness of nutritional compounds, such as polyphenols, phytosterols, and tocopherols. In comparison, BT was found to have a lower nutritional value than FRO but added a unique taste and aroma to the hotpot. The use of blended oil as raw oil could also improve the quality of hotpot oil. This information will provide an important guide to the nutritional value and industrial production of hotpot oil. Blended oil is a promising raw oil for future use in hotpot seasoning processing to meet consumer demands for nutritious and pleasantly flavored hotpot oil.     

Solid phase enzymatic glycerolysis of beef tallow resulting in a high yield of monoglyceride

A mixture of mono-, di- and triglycerides was obtained when beef tallow was reacted with glycerol using lipase enzyme as a catalyst. The reaction was carried out batchwise in a small vessel with agitation by magnetic stirring. The yield of monoglyceride (MG) was greatly influenced by the reaction temperature—at higher temperatures (48–50°C) a yield of approximately 30% MG was obtained, while at lower temperatures (38–46°C) a yield of approximately 70% MG was obtained. A sharp transition was observed between the high and low yield equilibrium states. The temperature at which this transition occurred is called the critical temperature (T_c) and was found to be 46°C in the case of tallow. During the course of the reaction, when approximately 40% MG had been synthesized, the reaction mixture became solid but the reaction continued until approximately 70% MG had been synthesized. A yield of 70% MG also was obtained with tallow at 42°C when a glycerol/tallow mole ratio ranging from 1.5 to 2.5 was used. The free fatty acid content at equilibrium depended on the water concentration in the glycerol phase and varied from 0.5% to 11.0% when the water content ranged from 0.6% to 12.5%. Above 8% water content, the yield of MG was reduced. Of the commercially available lipases that were investigated, lipase fromPseudomonas fluorescens orChromobacterium viscosum resulted in the highest yield of MG.     

Effect of enzymatic interesterification on the melting point of tallow-rapeseed oil (LEAR) mixture

To reduce the melting point of a tallow-rapeseed oil mixture, the triglyceride composition of the mixture was altered by enzymatic interesterification in a solvent-free system. The interesterification and hydrolysis were followed by melting point profiles and by free fatty acid determinations. The degree of hydrolysis was linearly related to the initial water content of the reaction mixture. The rate of the interesterification reaction was influenced by the amount of enzyme but not much by temperature between 50 and 70°C. The melting point reduction achieved by interesterification depended on the mass fractions of the substrates: the lower the mass fraction of tallow, the larger the reduction of the melting point.     

Enzymatic interesterification of tallow-sunflower oil mixtures

In an effort to improve the physical and/or thermal characteristics of solid fats, the enzymatic interesterification of tallow and butterfat with high-oleic sunflower oil and soybean oil was investigated. The two simultaneously occurring reactions, interesterification and hydrolysis, were followed by high-performance liquid chromatography of altered glycerides and by gas-liquid chromatography of liberated free fatty acids. The enzymes used in these studies were immobilized lipases that included either a 1,3-acyl-selective lipase or acis-9-C₁₈-selective lipase. The degree of hydrolysis of the fat/oil mixtures was dependent upon the initial water content of the reaction medium. The extent of the interesterification reaction was dependent on the amount of enzyme employed but not on the reaction temperature over the range of 50–70°C. Changes in melting characteristics of the interesterified glyceride mixtures were followed by differential scanning calorimetry of the residual mixed glycerides after removal of free fatty acids. Interesterification of the glyceride mixes with the two types of enzymes allowed for either a decrease or increase in the solid fat content of the initial glyceride mix.     

Comparison between conventional and ultrasonic preparation of beef tallow biodiesel

Tallow is biodiesel feedstock that, due to its highly centralized generation in slaughter/processing facilities and historically low prices, may have energetic, environmental, and economic advantages that could be exploited. Transesterification of fatty acids by means of ultrasonic energy has been used for biodiesel production from different vegetable oils. However, application of ultrasonic irradiation for biodiesel production from beef tallow has received little attention. In this work, the transesterification of beef tallow with methanol was performed in the presence of potassium hydroxide as a catalyst using ultrasound irradiation (400 W, 24 kHz). The reaction time, conversion and biodiesel quality were compared with that seen in conventional transesterification. The results indicated that the reaction conversion and biodiesel quality were similar; however, the use of ultrasonic irradiation decreased the reaction time, showing that this method may be a promising alternative to the conventional method.     

Interesterification of tallow and sunflower oil

The objective of this study was to manufacture a shortening using chemical interesterification (IT) of tallow-sunflower oil blends to replace fish oil in the present formulation, which is now in short supply in Chile. The significant variables of the IT process were obtained by 2⁴⁻¹ fractional factorial design. The proportion of tallow (T) in the blend, catalyst concentration, and reaction temperature had a significant effect on the melting point (mp) (P≤0.05). IT of tallow and sunflower oil blends (90∶10 and 70∶30) diminished the mp, dropping point, and refractive index compared to tallow. However, a noninteresterified 90∶10 blend mp was not significantly different from tallow. IT produced a solid fat content (SFC) profile of IT90∶10 blend that was appropriate for use in shortenings for the baking industry. Blending and IT of the 90∶10 blend increased the melting profile of the tallow and the melting range from −40 to 60°C while the endotherms of the middle-melting triacylglycerols (TAG) decreased. The IT90∶10 blend hardnesswas 70% lower than tallow hardness, and the crystal network was composed of large spherulites in a network. IT resulted in an appropriate method to improve physical properties of tallow, whereas blending did not significantly modify it. The interesterification changed the SFC profile of IT90∶10, giving a more appropriate shortening for use in the baking industry.     

Enzymatic transesterification of rapeseed oil and lauric acid in a continuous reactor

The optimum conditions for enzymatic transesterification of rapeseed oil and lauric acid in a fixed-bed reactor were studied. No solvent was used in the reaction mixture. A small amount of water was dissolved in the substrate mixture to maintain the activity of the enzyme at as high a level as possible. For maximum yield, the transesterification was performed with a residence time of about 20 min at a water content in the range of 0.1 to 0.2% and at the lowest possible temperature.     

Effects of extraction and fractionation pressures on supercritical extraction of cholesterol from beef tallow

Edible beef tallow was extracted by supercritical CO₂ in a dynamic mode at pressures from 138 to 345 bars and temperatures of 40 and 50°C. The lipid fractions were collected at 34.5 bar/40°C. A retrograde behavior of lipid solubility was observed around 170–175 bar. The ranges of the cholesterol concentration [chol.], were 300–450 mg/100 g and 50–200 mg/100 g lipid for the fractions extracted at 138 bar and 345 bar, respectively. Beef tallow was also extracted with sequentially varied pressures of 138, 345 and 138 bars at 40°C and collected at 34.5 bar/40°C. The results showed that after 20 kg CO₂ was used for extracting 100 g of loaded beef tallow the weight of the residual beef tallow remaining in the extractor was 23 g with [chol.] of 49 mg/100 g lipid. The lower [chol.] of the residual beef tallow represents a 60–70% reduction in cholesterol content, when compared with untreated beef tallow where [chol.] ranges from 130 to 160 mg/100 g lipid. To isolate lipid fractions containing higher [chol.], beef tallow was extracted at 345 bar/40°C and then fractionated into three separators connected in series with decreasing pressures of 173 bar, 117 bar, and 34.5 bar at 40°C, respectively. The results showed that the fractions collected from the third separator (34.5 bar) contained concentrated [chol.] ranging from 272 to 433 mg/100 g lipid. The fatty acid analysis revealed that the fractions containing high [chol.] generally consisted of high concentrations of myristic and palmitoleic acids but low concentrations of stearic and oleic acids.     

Optimization of enzymatic degumming process for rapeseed oil

An enzymatic process optimization and a largescale plant trial for rapeseed oil degumming were carried out by a novel microbial lipase. Response surface methodology was used to obtain the desired data in the process optimization. Enzyme dosage, temperature, and pH were important determining factors affecting oil degumming. The optimal set of variables was an enzyme dosage of 39.6 mg/kg, a temperature of 48.3°C, and a pH of 4.9. The phosphorus content could be reduced to 3.1 mg/kg at the optimal levels of the tested factors. An enzymatic degumming plant trial was performed on a 400 tons/d oil production line. pH was found to play an important role in degumming performance. When the pH was 4.6–5.1, the corresponding phosphorus content of degummed rapeseed oil could be reduced to less than 10 mg/kg, which met the demands of the physical refining process.     

High-yield diacylglycerol formation by solid-phase enzymatic glycerolysis of hydrogenated beef tallow

Diglyceride (DG) was prepared by reaction of hydrogenated beef tallow and glycerol in the presence of aPsesudomonas lipase. The yield of DG depended strongly on the reaction temperature. After initial incubation at 60°C for 2 h, followed by the first temperature shift down to 55°C for 4 h and then the second shift down to 48°C for up to 3 d, the reaction mixture became solid and a yield of approximately 90% DG was obtained. About 95% of total DG was 1,3-DG. The yield of DG was also dependent on the glycerol (GL) to triglyceride (TG) molar ratio. At the molar ratio of 1∶2 (GL/TG), the enzyme-catalyzed reaction was highly efficient and utilized essentially all of the glycerol. The free fatty acid (FFA) content at equilibrium depended on the water concentration in the glycerol phase. The initial rate of FFA formation was low and was hardly affected by the moisture content between 0.5 and 4%, but, at higher water content (4–6.7%), there was a small increase in the rate.     

Modification of margarine fats by enzymatic interesterification: Evaluation of a solid-fat-content-based exponential model with two groups of oil blends

Lipozyme TL IM-catalyzed interesterification for the modification of margarine fats was carried out in a batch reactor at 70°C with a lipase dosage of 4%. Solid fat content (SFC) was used to monitor the reaction progress. Lipase-catalyzed interesterification, which led to changes in the SFC, was assumed to be a first-order reversible reaction. Accordingly, the change in SFC vs. reaction time was described by an exponential model. The model contained three parameters, each with a particular physical or chemical meaning: (i) the initial SFC (SFC₀), (ii) the change in SFC (ΔSFC) from the initial to the equilibrium state, and (iii) the reaction rate constant value (k). SFC_o and ΔSFC were related to only the types of blends and the blend ratios. The rate constant k was related to lipase activity on a given oil blend. Evaluation of the model was carried out with two groups of oil blends, i.e., palm stearin/coconut oil in weight ratios of 90∶10, 80∶20, and 70∶30, and soybean oil/fully hydrogenated soybean oil in weight ratios of 80∶20, 65∶35, and 50∶50. Correlation coefficients higher than 0.99 between the experimental and predicted values were observed for SFC at temperatures above 30°C. The model is useful for predicting changes in the SFC during lipase-catalyzed interesterification with a selected group of oil blends. It also can be used to control the process when particular SFC values are targeted.     

Application of full factorial design and Doehlert matrix for the optimisation of beef tallow methanolysis via homogeneous catalysis

The transesterification of triglycerides by means of alkaline catalysts is the most widely used route for biodiesel production and reaction optimisation by multivariate methods has been used for biodiesel production from different vegetable oils. However, the application of simultaneous optimisation for biodiesel production from beef tallow has received little attention. In an effort to optimize the beef tallow biodiesel production, a combination of the full factorial design and the Doehlert matrix was applied, and the effects of temperature, reaction time, catalyst concentration and alcohol:tallow molar ratio and their reciprocal interactions were assessed. The response variables under study were purity and yield of the final biodiesel product. In the selected condition [alcohol:tallow molar ratio (M) = 7.5:1, catalyst:tallow mass ratio (C) = 1.5%, reaction time (t) = 20 min and temperature = 50 °C], the conversion yield of tallow biodiesel was 88.4% and the purity was 99.4%. The final biodiesel obtained was analysed and showed to have good quality characteristics.     

Conjugated linoleic acid (CLA) production and lipase‐catalyzed interesterification of purified CLA with canola oil

In this study, two important isomers of CLA, i.e. c9,t11 and t10,c12, were produced up to ca. 73% of total fatty acids, employing alkali isomerization of safflower oil, followed by purification with only one‐step urea crystallization to 85.6%, while the recovery of the purification process was 35%. Interesterification (acidolysis) of purified CLA with canola oil was then conducted by Thermomyces lanuginosus lipase. The CLA content incorporated into the triacylglycerols (TG) was 26.6 mol‐% after 48 h of reaction time. Physical and chemical properties of the TG were then changed according to the degree of substitution of oleic acid in canola oil with CLA.     

Production of cocoa butter-like fats by the lipase-catalyzed interesterification of palm oil and hydrogenated soybean oil

Cocoa butter-like fats were prepared from refined, bleached, and deodorized palm oil (RBD-PO) and fully hydrogenated soybean oil (HSO) by enzymatic interesterification at various weight ratios of substrates. The cocoa butter-like fats were isolated from the crude interesterification mixture by fractional crystallization from acetone. Analysis of these fat products by RP-HPLC in combination with ELSD or MS detection showed that their TAG distributions were similar to that of cocoa butter but that they also contained MAG and DAG, which were removed by silica chromatography. The optimal weight ratio of RBD-PO to HSO found to produce a fat product containing the major TAG component of cocoa butter, namely, 1(3)-palmitoyl-3(1)-stearoyl-2-monoolein (POS), was 1.6∶1. The m.p. of this purified product as determined by DSC was comparable to the m.p. of cocoa butter, and its yield was 45% based on the weight of the original substrates.     

Volatile fatty acids in flavors of potatoes deep-fried in a beef blend

The volatile free fatty acids were analyzed in commercial french- fried potatoes that had been deep- fried in beef tallow- hydrogenated vegetable oil shortening. The results showed that many of the volatile fatty acids present in beef tallow were transferred to the potatoes. Of the fatty acids derived from beef tallow, butanoic, 2-methylbutanoic, 3- methylbutanoic, heptanoic, 4-methyltanoic, and nonanoic acids were present in concentrations above their respective thresholds, and should contribute to tallow- like flavors. Several unsaturated volatile fatty acids also were identified, and they should contribute to the general deep- fried potato flavor.     

Influence of interesterification on the oxidative stability of marine oil triacylglycerols

To understand the relationship between triacylglycerol structure of marine oils and their oxidative stability, peroxide values and absorbed oxygen levels of whale, sardine, cod liver and skipjack oils, interesterified by lipase and NaOCH₃, were compared with those of native oils during storage at 40°C. Triacylglycerol structures of marine oils were characterized by high-performance liquid chromatography and differential scanning calorimetry analyses. Enzymatically interesterified fish oils were more stable than native oils because the level of highly unsaturated triacylglycerols was decreased. However, the oxidative stability of interesterified whale oil was more susceptible to oxidation than the native oil.