Physical, chemical and stability properties of buffalo butter oil fractions obtained by multi-step dry fractionation

Dry fractionation efficiency of milk fats from different sources and the characteristics of their fractions in chemical composition, thermal property, and crystal morphology

The physicochemical properties of anhydrous milk fats (AMF) often change according to different regions and seasons, inevitably affecting dry fractionation. This study analyzed the differences in the fraction yields and physicochemical characteristics of four AMFs from different sources. The results showed that single-stage dry fractionation conducted at 25 °C easily separated AMFs into liquid fractions (L25) and solid fractions (S25) via pressure filtration, both producing satisfactory yields. Moreover, all L25s exhibited few crystals with good fluidity at 25 °C, while S25s presented as semi-solids supported by β crystal networks with a certain hardness and plasticity. However, four AMFs displayed fractionation efficiency variation, while the thermal differences among them showed no obvious correlation with those among their fractions. Generally, more trisaturated triglycerides with 48 to 54 carbon atoms in the AMF increased the S25 yield and decreased the slip melting points (SMP) of both fractions.

Compositional characteristics of dairy products and their potential nondairy applications after shelf-life

Many dairy products are discarded and useless after end of shelf-life, which causes economic and environmental challenges. The objective of this study was to study the compositional characteristics of some dairy products before and after shelf-life, and develop a process to utilize those dairy products after end of shelf-life in non dairy applications (cosmetic cream and soap). Several dairy products, such as sterilized milk, yogurt, soft cheese, hard cheese, cream, and butter were collected from markets in Egypt before shelf-life and after three months of shelf-life. Electrophoresis analysis was conducted to estimate the changes in the protein fractions of protein products (sterilized milk, yogurt, and cheese) before and after expiration. Also, gas chromatography (GS) was performed to compare the fatty acids of fat products (cream and butter) before and after end of shelf-life. Sterilized milk, yogurt, soft, and hard cheese were turned into powder (Expired dairy products powder; EDPP) to be used as a raw material in manufacturing of cosmetic creams. The fat was separated from cream, butter, and hard cheese (Expired dairy products fat; EDPF) to be utilized in making soap. The formulated cosmetic creams were examined in vitro. Functional properties of cream were determined, such as appearance, spreadability, irritancy, and pH. Additionally, the soap quality was tested after manufacture. We found that dairy products, such as milk, yogurt, and cheese after shelf-life can be utilized as raw materials for the production of cosmetic creams, as well as production of soap from butter and cream. The produced products were similar to those in commercial markets. This study is an endeavor to conquer the dairy industry challenges, which are considered a huge loss from the economic and environmental aspects.

•

Several dairy products were collected from markets before and after shelf-life.

•

The protein fractions were estimated in those dairy products before and after expiration.

•

Sterilized milk, yogurt, soft, and hard cheese after end of shelf-life were turned into powder.

•

This powder can be used as a raw material in manufacturing of cosmetic creams.

•

The fat of expired dairy products was used in making soap.

A novel approach for the reconstitution of bovine milk fat globules with different-melting-temperature triacylglycerol cores

Reconstructing milk fat globules (MFG) with different-melting-temperature triacylglycerols (TAG) to improve its nutritional and functional properties has great potential for expanding industrial applications. Butterfat was fractionated by stepwise crystallization at 30, 20 and 15 °C to yield six fractions (30S, 30L, 20S, 20L, 15S and 15L). Fractions were analyzed for thermal properties and fatty acid composition. An efficient method for analyzing TAG was established using HPLC-ESI-Q-TOF-MS/MS combined with principal component analysis, and total 146 TAGs in butterfat and its fractions were identified. The melting enthalpy, melting temperature, and long-chain saturated TAG content of 30S fraction were 71.5 J/g, 42.1 °C, and 19.3%, respectively, while that of 15L fraction corresponded to 11.9 J/g, 17.1 °C and 0.1%, indicating that the butterfat was effectively separated. Then MFG were reconstituted with milk fat globule membrane and different-melting-temperature TAG cores from obtained fractions, and reconstituted MFG gave excellent microstructural stability and emulsifying activity.

Research of milk fat oxidation processes during storage of butter pastes

Basic quality indicators studied: acidity, peroxide, anisidine value and integrated value of complete fat oxidation. Butter paste was selected as a reference, consisting of butter, skim milk powder and fat-soluble emulsifiers. Peroxide value during storage at the temperature of (4 ±2 °С) for the first 4 days did not exceed 5.0 1/2 О mmol.kg-1, on the 15th day fat peroxide value of butter paste with milk-vegetable protein exceeded permissible limits that is indicative of milk fat contamination. At the temperature of (-3 ±1 °С) butter paste fat couldn't be qualified as fresh when storing during 15 days, peroxide value exceeds permissible limits on the 25th day of storage. Rising of the peroxide value above 5 1/2 О mmol.kg-1 was detected on the 25th day of storage, exceeding of threshold value was on the 45th day. It was established that rate of oxidation processes in butter pastes with vegetable protein is the highest among all studied samples in each particular control and observation point. It was determined that the rate of secondary lipid oxidation depends on the storage temperature and is observed when storing butter paste samples at a temperature of (-3 ±1 °С) on the 10th day, (-24 ±2 °С) – on the 30th day of storage. Acid value did not exceed recommended limits (2.5 °K) and was on average – 2.3 °K when storing butter paste during 10 days at a temperature of (4 ±2 °С); 2.1 °K during 20 days at the temperature of (-3 ±1 °С), 2.4 °K during 40 days at the temperature of (-24 ±2 °С). In view of obtained results of fat phase stability evaluation of studied butter pastes, the following storage maximum time is recommended: at the temperature of (4 ±2 °С) ‒ 7 days, at the temperature of (-3 ±1 °С) – 15 days, at the temperature of (-26 ±2 °С) ‒ 30 days.

Unsaturated fat fraction from lard increases the oxidative stability of minced pork

Lard from pork back fat was dry fractionated based on crystallization temperature, resulting in fractions with a ratio of saturated to unsaturated fatty acids of 1.10 and 0.61. Lean minced pork was mixed with the saturated and unsaturated fat fraction and stored in modified atmosphere (80% O₂ and 20% CO₂) at 5 °C for 2, 5, 7, 9, and 12 days under light to investigate the effect on oxidative stability of lipids and proteins. The saturated fat group developed higher TBARS values and lower levels of free thiol groups during storage, indicating that the unsaturated fat fraction in minced pork promoted increased oxidative stability of both lipids and proteins. A higher content of α-tocopherol in the unsaturated fat fraction suggests that the differences in oxidative stability is causatively linked to the balance between the fatty acid composition and content of antioxidants. The TBARS values and free thiol content were negatively correlated, suggesting a relationship between lipid and protein oxidation.

Characterization of a New α-Linolenic Acid-Rich Oil: Eucommia ulmoides Seed Oil

Eucommia ulmoides seed oil is the main byproduct of E. ulmoides cultivation. To better understand its functions, E. ulmoides seed oil is characterized comprehensively in this work. The composition of E. ulmoides seed, physicochemical properties, thermal properties, fatty acid composition, triacylglycerol (TAG) composition and Vitamin E composition of E. ulmoides seed oil were determined. The results show that the E. ulmoides seed contained about 34.63% oil. The excellent physicochemical properties of E. ulmoides seed oil ensured it has a potential to be developed as an edible oil. The main fatty acids in E. ulmoides seed oil were linolenic acid (61.36%), oleic acid (17.02%), and linoleic acid (12.04%). HPLC-ELSD method determined that LnLnLn (37.99%), LnLnO (22.62%), LnLnL (14.5%), and LnLnP (8.78%) were the oil's major TAG components. The oil exhibited a unique thermal curve which contained 2 melting peaks at -38.45 and -22.22 °C, respectively. The total content of vitamin E in E. ulmoides seed oil was 190.96 mg/100g, which exist mainly in γ-tocopherol and δ-tocopherol isomer. Overall, the results indicated that E. ulmoides seed oil is a promising oil in food, pharmaceutics, cosmetics and other nonfood industries.

Production and physicochemical properties of functional-butterfat through enzymatic interesterification in a continuous reactor

Modified-butterfat (MBF) was synthesized with four blends (8:6:6, 6:6:8, 6:6:9, and 4:6:10, by weight) of anhydrous butterfat (ABF), palm stearin (PS) and flaxseed oil (FSO) through enzymatic interesterification in a continuous packed-bed reactor. Flow rate effect of 3, 5, 8 and 10 mL/min on enzymatic interesterification was investigated. By increasing the enzyme contact time with substrates (decreased flow rates), not only did melting and crystallization points shift to lower temperature but also the equivalent carbon number, ECN 36-38 from FSO decreased. Further all reactions were performed at flow rate of 5 mL/min (contact time 140 min) in a continuous reactor packed with 150 g of Lipozyme RM IM. After short path distillation, alpha-linolenic acid composition (%) of 8:6:6, 6:6:8, 6:6:9, and 4:6:10 MBFs were 16, 21, 23 and 25%, respectively. The contents of ECN 36-38, and ECN 48-50 decreased in the blends and MBFs for each substrate ratio. ECN 42-46 in the newly produced TAG increased. Melting points of MBFs were 38 degrees C (8:6:6), 35.5 degrees C (6:6:8), 34 degrees C (6:6:9), and 32 degrees C (4:6:10). MBFs interesterified with FSO contained phytosterols (17-36 mg/100 g) and tocopherols (116-173 microg/g). The products of 8:6:6, 6:6:8, 6:6:9 and 4:6:10 MBFs were softer (69, 88, 80, and 92%, respectively) than pure butterfat at refrigeration temperature. The polymorphic form changed from beta form (blends) to desirable crystalline structure of beta' form (MBFs). Crystal morphology of MBFs also changed and was composed of small spherulites of varying density.