Characterization and stability of solid lipid nanoparticles produced from different fully hydrogenated oils.

The use of lipids from conventional oils and fats to produce solid lipid nanoparticles (SLN) attracting interest from the food industry, since due their varying compositions directly affects crystallization behavior, stability, and particle sizes (PS) of SLN. Thus, this study aimed evaluate the potential of fully hydrogenated oils (hardfats) with different hydrocarbon chain lengths to produce SLN using different emulsifiers. For that, fully hydrogenated palm kern (FHPkO), palm (FHPO), soybean (FHSO), microalgae (FHMO) and crambe (FHCO) oils were used. Span 60 (S60), soybean lecithin (SL), and whey protein isolate (WPI) were used as emulsifiers. The physicochemical characteristics and crystallization properties of SLN were evaluated during 60 days. Results indicates that the crystallization properties were more influenced by the hardfat used. SLN formulated with FHPkO was more unstable than the others, and hardfats FHPO, FHSO, FHMO, and FHCO exhibited the appropriate characteristics for use to produce SLN. Concerning emulsifiers, S60- based SLN showed high instability, despite the hardfat used. SL-based and WPI-based SLN formulations, showed a great stability, with crystallinity properties suitable for food incorporation.

Developed and characterization of nanostructured lipid carriers containing food-grade interesterified lipid phase for food application.

The main objectives of our work were to produce new nanostructured lipid carriers (NLCs) from interesterified and simple lipid phases and to study the influence of lipid composition on the physical characteristics and stability of NLCs. We used conventional oils and fats already used in lipid-based foods, in addition to soy lecithin as a natural emulsifier. The NLCs were formulated using as lipid phase, simple and interesterified blends composed of soybean oil as liquid lipid and fully hydrogenated oils from palm, soybean, microalgae, and crambe as solid lipids. NLCs were produced using high-pressure homogenization. NLCs were influenced by chemical interesterification and by the composition of the solid lipid used, mainly in relation to the fatty acid chain size. NLC formulations developed with a simple lipid phase were 256-323 nm (d32) in size, with zeta potential values ranging from -36.93 to -42.87 mV after 60 days of storage. NLCs developed with the interesterified lipid phase were 250-288 nm (d32) in size, with zeta potential values ranging from -40.17 to -44.20 mV after 60 days of storage. NLCs produced with saturated fatty acids with larger chain sizes showed larger particle sizes but showed less variation in this parameter over storage. Interesterification reduced the melting temperature of NLCs, indicating decreased crystallinity and a less organized structure. Moreover, interesterification favored crystals in the ß' form, which is a positive characteristic for incorporating bioactive compounds. Thus, the systems developed in this study are innovative, mainly in terms of the composition of the NLCs, and have good potential for food applications.

Design of new lipids from bovine milk fat for baby nutrition.

The lipid phase of infant formulas is generally composed of plant-based lipids structured with a high concentration of palmitic acid (C16:0) esterified at the sn-2 position of triacylglycerol since this structure favors the absorption and metabolism of fatty acids. Palm oil is commonly used to make up the lipid phase of infant formulas due to its high concentration of palmitic acid and solids profile and melting point similar to human milk fat. However, the addition of palm oil to infant formulas has been associated with the presence of 3-monochloropropane-1,2-diol (3-MCPD) esters, a group of glycerol-derived chemical contaminants (1,2,3-propanotriol), potentially toxic, formed during the refining process of vegetable oil. Bovine milk fat obtained from the complex biosynthesis in the mammary gland has potential as a technological alternative to replace palm oil and its fractions for the production of structured lipids to be used in infant formulas. Its application as a substitute is due to its composition and structure, which resembles breast milk fat, and essentially to the preferential distribution pattern of palmitic acids (C16:0) with approximately 85% distributed at the sn-1 and sn-2 position of triacylglycerol. This review will address the relationship between the chemical composition and structure of lipids in infant nutrition, as well as the potential of bovine milk fat as a basis for the production of structured lipids in substitution for the lipid phase of vegetable origin currently used in infant formulas.

Effect of processing on the bioaccessibility of essential minerals in goat and cow milk and dairy products assessed by different static in vitro digestion models.

The study evaluated the effect of goat and cow milk processing on the bioaccessibility of calcium, magnesium and zinc using different methods following the static in vitro simulation of gastrointestinal digestion: solubility and dialysis models. Raw goat and cow milks were processed to obtain pasteurized milk, yogurt and cheese. In general, goat milk and dairy products presented higher bioaccessibility of Ca and Mg than cow milk and dairy products. The milk processing affected the minerals bioaccessibility indicating the importance of food structure, composition and minerals equilibrium on the in vitro digestion and bioaccessibility prediction. The potential absorptions of Ca and Zn were higher in cheeses when compared to the milks and yogurts, independently of the method used. The minerals bioaccessibility evaluated by the solubility method was higher than the obtained by dialysis method for all the products evaluated.

Artisanal Brazilian Cheeses-History, Marketing, Technological and Microbiological Aspects.

This review focused on the historical, marketing, technological, and microbiological characteristics of artisanal Brazilian cheese. Brazilian cheese production was introduced and developed from the influence of immigrants considering the combination of climate, races of the animals, quality and specificity of milk, technological cheese-making processes and environmental microbiology, among other factors. It resulted in cheese products with specific physicochemical, microbiological, and sensory quality, which represent the heritage and identities of the different Brazilian regions. The production of artisanal cheese increased in many Brazilian regions, mainly in the southeast, especially due to the traditional production and innovative development of new varieties of cheese. The microbiological quality and safety of raw-milk artisanal cheese continues to be a concern and many studies have been focusing on this matter. Special attention needs to be given to the cheeses produced by raw milk, since numerous reports raised concerns related to their microbiological safety. This fact requires attention and the implementation of strict hygiene practices on the production and commercialization, besides appropriate governmental regulations and control. However, more studies on the relationship between technological processes and microbiological properties, which results in a superior culinary quality and safety of artisanal Brazilian cheeses, are needed.

Bioactive peptides in ripened cheeses: release during technological processes and resistance to the gastrointestinal tract.

Milk proteins are recognized as the main source of biologically active peptides. Casein's primary structure contains several bioactive amino acid sequences on its latent inactive form. These potential active sequences can be released during cheese manufacture and ripening, giving rise to peptides with biological activity such as antihypertensive, antidiabetic, antioxidant, immunomodulatory, and mineral-binding properties. However, the presence of biopeptides in cheese does not imply actual biological activity in vivo because these peptides can be further hydrolyzed during gastrointestinal transit. This paper reviews the recent advances in biopeptide formation in ripened cheeses production, focusing on the influence of technological parameters affecting proteolysis and the consequent release of peptides. The main discoveries in the field of cheese peptide digestion through recent in vivo and in vitro model studies are also reviewed. © 2021 Society of Chemical Industry.

Monensin residues in the production of Minas Frescal cheese: Stability, effects on fermentation, fate and physicochemical characteristics of the cheese.

Considering the widespread use of the antibiotic monensin (MON) in the Brazilian livestock and the possibility of residues in milk, this paper aimed to study the stability and fate of this drug during the production of Brazilian Minas Frescal cheese, its effects on milk fermentation and on the physicochemical characteristics of this product. For that, samples of raw milk were fortified with MON at three different nominal concentrations (1.0, 2.0 and 8.0 µg/kg), passed through heat treatment and used to produce Minas Frescal cheese. Pasteurization efficiency was certified by alkaline phosphatase and peroxidase enzyme tests and cheese samples were evaluated for pH, moisture and total protein and fat content. MON residues were determined by LC-MS/MS in the following steps: raw milk, heat-treated milk, whey and cheese. No significant degradation of MON due to heat treatment was observed, suggesting that the drug is resistant to high temperatures. Moreover, the residue levels quantified in cheese and whey demonstrated a concentration of this antibiotic in the curd by about 5-fold, with a small amount of MON being lost during draining. There were no significant differences (p > 0.05) considering the physicochemical parameters evaluated in cheese samples. Fermentation was also not affected by the presence of the drug. The results showed that residues of MON in milk are stable during cheese production and may be concentrated in the final product, as well as indicate the need to establish a MON safe residue level for this food commodity.

Milk fat nanoemulsions stabilized by dairy proteins.

Droplet size, polydispersity, physical and polymorphic stability of milk fat nanoemulsions produced by hot high-pressure homogenization and stabilized by whey protein isolate (WPI pH 4.0 or 7.0) or sodium caseinate (NaCas pH 7.0) were evaluated for 60 days of storage at 25 °C. Smaller droplets were observed for the NaCas pH 7.0 nanoemulsion, which also showed a lower polydispersity index, resulting in a stable emulsified system for 60 days. On the other hand, the nanoemulsion with bigger droplet size (WPI pH 4.0) showed reduced stability, probably due to the pH near the isoelectric point of the whey proteins. The nanostructured milk fat exhibited the same melting behavior as the bulk milk fat, with a balance between liquid and crystallized fat, and crystals in polymorphic form ß'. This could be an advantage concerning the application of the system for delivery of bioactive compounds and improvement of the sensory properties of fat-based food. In summary, nanoemulsions stabilized by NaCas (pH 7.0) showed higher kinetic stability over the storage time, which from a technological application point of view is a very important factor in the food industry.

Peptide profile and angiotensin-converting enzyme inhibitory activity of Prato cheese with salt reduction and Lactobacillus helveticus as an adjunct culture.

Among strategies to improve the health-related aspects of dairy products, great prominence has been given to salt reduction and the use of adjunct cultures that can favor the release of bioactive peptides during cheese ripening. This study aimed to evaluate the effect of the salt reduction, the addition of Lactobacillus helveticus LH-B02 and the ripening time of Prato cheese on the casein hydrolysis profile by capillary electrophoresis, peptide profile by mass spectrometry, and antihypertensive potential evaluated in vitro through the inhibitory activity of the angiotensin-converting enzyme (ACE). Both the salt reduction and the addition of adjunct culture favored the accumulation of the bioactive peptide ß-CN (f193-209) (m/z 1881). The adjunct culture led to a higher ACE inhibitory activity during the ripening of Prato cheese, thus proving to be an effective strategy for the development of potentially bioactive cheese.

Physicochemical characteristics of anhydrous milk fat mixed with fully hydrogenated soybean oil.

There is a growing demand for fats that confer structure, control the crystallization behavior, and maintain the polymorphic stability of lipid matrices in foods. In this context, milk fat has the potential to meet this demand due to its unique physicochemical properties. However, its use is limited at temperatures above 34 °C when thermal and mechanical resistance are desired. The addition of vegetable oil hard fats to milk fat can alter its physicochemical properties and increase its technological potential. This study evaluated the chemical composition and the physical properties of lipid bases made with anhydrous milk fat (AMF) and fully hydrogenated soybean oil (FHSBO) at the proportions of 90:10; 80:20; 70:30; 60:40; and 50:50 (% w/w). The increased in FHSBO concentration resulted in blends with higher melting point, which the addition of 10% of FHSBO increase the melting point in 12 °C of the lipid base. Also, FHSBO contributed for a higher thermal resistance conferred by the coexistence of polymorphs ß' and ß, which remained stable for 90 days. Co-crystallization was observed for all blends due to the total compatibility of milk fat with the fully hydrogenated soybean oil. The results suggest a potential of all blends for various technological applications, makes milk fat more appropriate to confer structure, and improve the polymorph stability in foods. The blends presenting singular characteristics according to the desired thermal stability, melting point, and polymorphic habit.

Dairy-based solid lipid microparticles: A novel approach.

The objective of this work was to produce solid lipid microparticles using fully hydrogenated anhydrous milk fat (FHAMF) and to evaluate their physical stability during 90 days of storage at different temperatures. To obtain the lipid microparticles, the FHAMF was sprayed in a double fluid atomizer at 1 bar pressure, in a chilled chamber (2 °C). After atomization, the microparticles were divided into three batches and stored for 90 days at three different temperatures (5, 15 and 25 °C). During storage, samples were periodically removed (7, 15, 30, 60 and 90 days) for evaluation of particle size, melting behavior, morphology, and polymorphic habit. The microparticles presented spherical shaped, with a smooth surface and wide size variation. When stored at 5 °C, the microparticles showed the smaller size and smaller agglomeration, due to the lower liquid fat content in the system, which that makes it difficult the adhesion of one particle to another. The lipid microparticles presented ß' crystals immediately after processing and at all temperatures during the storage. This study demonstrated the potential of FHAMF as an appropriate lipid phase for the production of lipid microparticles, and may contribute to further studies on the delivery of active compounds.

Milk fat crystal network as a strategy for delivering vegetable oils high in omega-9, -6, and -3 fatty acids.

As an alternative to the strategies currently used to deliver unsaturated fatty acids, especially, the essentials omega-6 and 3- fatty acids, the aim of this work was to investigate the effect of the incorporation of 25 e 50% (w/w) of olive, corn and linseed oil into the crystal structure of anhydrous milk fat (AMF). Fatty acid composition, atherogenicity (AI), and thrombogenicity (TI) index, crystallization kinetics, polymorphism by Rietveld method (RM), microstructure, thermal behavior, solid fat content, and lipid compatibility was evaluated. The addition of vegetable oils reduced the saturated fatty acids, and the AI and TI indices of AMF, and increased the concentration of unsaturated, specifically omega-6 and -3 fatty acids. Although vegetable oils caused changes in nucleation and crystallization kinetics, the spherulitic and crystalline morphology and the ß' polymorphism of AMF were maintained. The study demonstrated the possibility of using the crystal structure of AMF as a vehicle for unsaturated fatty acids in food formulations, as an alternative to nutritional supplementation. In addition, studies on the use of RM in blends made with AMF and vegetable oil have not been found in literature, thus demonstrating the relevance of the present study.

Potential of Milk Fat to Structure Semisolid Lipidic Systems: A Review.

Food production and consumption patterns have changed dramatically in recent decades. The universe of oils and fats, in particular, has been changed due to the negative impacts of trans fatty acids produced industrially through the partial hydrogenation of vegetable oils. Regulations prohibiting its use have led the industry to produce semisolid lipid systems using chemical methods for modification of oils and fats, with limitations from a technological point of view and a lack of knowledge about the metabolization of the modified fats in the body. Milk fat is obtained from the complex biosynthesis in the mammary gland and can be a technological alternative for the modulation of the crystallization processes of semi-solids lipid systems, once it is naturally plastic at the usual processing, storage, and consumption temperatures. The natural plasticity of milk fat is due to its heterogeneous chemical composition, which contains more than 400 different fatty acids that structure approximately 64 million triacylglycerols, with a preferred polymorphic habit in ß', besides other physical properties. Therefore, milk fat differs from any lipid raw material found in nature. This review will address the relationship between the chemical behavior and physical properties of semisolid lipids, demonstrating the potential of milk fat as an alternative to the commonly used modification processes.

Peptide profile of Camembert-type cheese: Effect of heat treatment and adjunct culture Lactobacillus rhamnosus GG.

Several factors might impact the proteolysis during cheese manufacture and ripening and, therefore, the release of bioactive peptides. These factors include the heat treatment of the milk, the type of starter and secondary culture used and the ripening time. Thus, the objective of this study was to evaluate the effect of the milk heat treatment and the use of adjunct culture in the development of the peptide profile of Camembert-type cheese during ripening. The cheeses were made from raw and heat-treated milk, with and without the addition of Lactobacillus rhamnosus GG. The results obtained by mass spectrometry (MALDI ToF/MS) and analyzed by chemometrics (PLS-DA) revealed a complex hydrolysis profile of the caseins with 103 peaks found, of which 70 peptides were identified and 15 presented bioactive potential. The potential bioactive peptides important for the separation of cheeses were all derived from ß-casein. The heat treatment of the milk, the addition of the adjunct culture and the ripening time affected the peptide profile of the cheeses. At the beginning of ripening the cheeses presented a very similar peptide profile, which differed over time, and this differentiation is clearer for cheeses obtained from raw milk.

Improvement in the functionality of spreads based on milk fat by the addition of low melting triacylglycerols.

Although butter is valued for its characteristic flavor and aroma, it has the disadvantage of unsatisfactory spreadability at low temperatures. To increase the butter functionality, modifications have been proposed by associating the physical and nutritional characteristics. In this study, lipid bases composed of anhydrous milk fat (AMF) and high oleic sunflower oil (HOSO) were used in butter formulations, and the physicochemical characteristics and the physical properties were evaluated. Lipid bases made from AMF:HOSO blends at 70:30, 60:40, and 50:50 (% w/w) were emulsified in skimmed milk, and added to milk cream (35% fat) prior to the beating step. The control butter (cream with 35% fat) and spreads were stored for 30 days at 5 °C and evaluated for the physicochemical properties, fatty acids composition, solid fat content, melting point, crystallization parameters, thermal stability, hardness, melting behavior, and polymorphism. The increase in HOSO content significantly reduced hardness of the spreads, which increased during storage for all formulations. A preference for crystallization in the polymorphic habit ß' was observed for both butter and spreads during 30 days of refrigerated storage. However, there was a tendency for crystal formation in the ß form, which suggests the formation of unstable crystals during processing and storage of the products. The modification of functionality allowed obtaining softer structured milk fat products with increased concentration of unsaturated fatty acids, without the use of chemical modifications of oils and fats.

Milk fat as a structuring agent of plastic lipid bases.

The global legislation regarding the elimination of trans fat in foods has led to the need for technological solutions to produce plastic fats. Currently, the industrial method used to obtain lipid bases with different physical properties is the chemical interesterification of blends from hardfats and vegetable oils. Milk fat can be an alternative to this process, which is natural plastic fat, as a structurant to obtain plastic lipid bases containing vegetable oils. This study aimed to evaluate the ability of the anhydrous milk fat (AMF) to structure lipid bases made from AMF and high oleic sunflower oil (HOSO) (~80% oleic acid) blends. The blends were prepared in the following AMF:HOSO proportions (% w/w): 100:00 (control); 90:10; 80:20; 70:30; 60:40; and 50:50, and characterized for fatty acid and triacylglycerol composition, solid fat content, compatibility, melting point, thermal behavior of crystallization and melting, crystallization kinetics, microstructure, polymorphism and hardness. All blends showed compatibility between the constituents, which is fundamental for the stability of plastic fats. The anhydrous milk fat governed the crystallization of these lipid bases, presenting crystals of <30 µm of diameter, crystallized in polymorphic form ß'. The blends 70:30, 60:40 and 50:50 AMF:HOSO exhibited suitable profile for technological applications in the food industry, characterized by a solid fat content lower than 32% at 10 °C, and higher than 10% at 21 °C, and melting point near the body temperature.

A Survey of the Peptide Profile in Prato Cheese as Measured by MALDI-MS and Capillary Electrophoresis.

In this study, we describe the characterization of the peptide profile in commercial Prato cheese by matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) and capillary electrophoresis (CE). Ten commercial Prato cheese brands were characterized via their physicochemical composition and subjected to fractionation according to solubility at pH 4.6. The pH 4.6 insoluble fraction was evaluated by CE, whereas MALDI-MS was applied to the fraction soluble at pH 4.6 and in 70% ethanol. CE revealed a characteristic pattern of hydrolysis, with formation of para-κ-casein, hydrolysis of αs1 -casein at the Phe23 - Phe24 bond, and hydrolysis of ß-casein. For the MALDI-MS data, a complex peptide profile was observed, with the identification of 44 peptides previously reported (24 peptides from αs1 -casein, 14 from ß-casein, 3 from κ-casein, and 3 from αs2 -casein). It was also observed that cheeses with salt-in-moisture content greater than 5% showed an accumulation of a bitter-tasting peptide (m/z 1536, αs1 -CN f1-13), suggesting a relationship between the higher salt concentration and the abundance of this peptide. In conclusion, the results showed that even commercial cheeses produced with different raw material and processing conditions showed very similar peptide profiles when assessed at the molecular level, and only 9 peptides were responsible for discrimination of cheeses.

Efeito de níveis crescentes de uréia na dieta de vacas leiteiras sobre a composição e rendimento de fabricação de queijos minas frescal / Effect of increasing level of dietary urea in diets for dairy cows on composition and yield of Minas Frescal cheese

O objetivo do trabalho foi avaliar a substituição do farelo de soja por níveis crescentes de uréia na dieta de vacas leiteiras e os seus efeitos sobre a composição e o rendimento de fabricação de queijo Minas Frescal. Para a fabricação dos queijos, foram utilizados 15 kg de leite, provenientes de nove vacas Holandesas em lactação, distribuídas em três quadrados latinos 3x3. Foram utilizadas três dietas: A) controle, formulada para suprir 100% das exigências de proteína bruta, proteína degradável no rúmen (PDR) e proteína não degradável no rúmen(PNDR), utilizando farelo de soja como principal fonte protéica; B)com a inclusão de 0,75% de uréia, em substituição parcial ao farelo de soja, e C) com inclusão de 1,5% de uréia, em substituição parcial ao farelo de soja. Todas as dietas foram iso energéticas (1,53 Mcal/kg de energia líquida de lactação) e isonitrogenadas (16% de PB) e utilizaram cana-de-açúcar como volumoso. Quando analisados por regressão polinomial simples, os resultados da composição e da fração nitrogenada do leite pasteurizado não foram influenciados pelo nívelde uréia na dieta, o mesmo ocorrendo com a composição (pH,umidade, gordura, matéria mineral, cloreto de sódio, proteína bruta, nitrogênio solúvel em pH 4,6 e em TCA 12%) e o rendimento de fabricação dos queijos. Com base nos resultados deste estudo, conclui-se que o uso de até 1,5% de uréia na alimentação de vacas em lactação não alterou a composição do leite pasteurizado, bem como a composição e o rendimento de fabricação de queijo Minas Frescal.

The aim of this study was to evaluate the substitution of soybean meal for increasing levels of dietary urea on the composition and yield of Minas cheese. For each cheese making process, 15 kg of milk were collected from nine lactating Holstein cows that were arranged in 3 Latin squares. Three diets with sugar cane as roughage were fed for cows and consisted of: A) control diet formulated to provide 100% of the requirements of crude protein (CP), rumen undegradable protein (RUP) and rumen degradable protein (RDP), using soybean meal; B) urea inclusion at 0.75% of dry matter in substitution for soybean meal crude protein equivalent; C) urea inclusion at 1.5% of dry matter in substitution for soybean meal crude protein equivalent. Energy and protein levels of rations comply with NRC (2001), and were isoenergetic and isonitrogenous. When the data were analyzed by simple polynomial regression, no effect of treatments were observed on pasteurized milk composition and milk nitrogen fractions, as well as for cheese composition (pH, moisture,fat, ash, sodium cloride, crude protein, soluble nitrogen in pH 4,6 and in TCA 12%) and cheese yield. Based on the results of this study, it can be concluded that the addition of urea up to 1.5% in dry matter basis in substitution for soybean meal in the diet of Holstein cows did not alter cheese composition and yield.