Study on physicochemical properties, fatty acids, texture, antioxidant and antibacterial activities of ghee from different regions

Due to the lack of basic information on Chinese ghee and the increasing demand of consumers for natural oils, this study aims to explore and distinguish the quality characteristics of ghee in different regions of China. Ghee samples from 16 regions of Qinghai Province, Gansu Province, Xinjiang Uyghur Autonomous Region, and Tibet Autonomous Region were selected and their physicochemical properties, fatty acids, texture, antioxidant and antibacterial activities were determined. The results showed that: (1) The physicochemical properties of ghee were different from different regions, but the freshness and fat content are generally high. The results of iodine value and saponification value suggest that the fatty acid composition is good; (2) The unsaturated fatty acid/saturated fatty acid content of ghee in Tibet and Xinjiang ranges from 63.05% to 79.13%, which is better than that in other regions; (3) Gansu Diebu ghee has the highest hardness (40.69 N); (4) Ghee from different regions has good antioxidant activity, DPPH free radical scavenging activity is 30.45% to 58.06%, ABTS free radical scavenging activity is 41.14% to 65.53%, and has varying degrees of inhibition on gram-positive bacteria. In addition, yak ghee, cattle-yak ghee and cow ghee have better fatty acid composition and antibacterial ability than scalper ghee. The results of this study distinguish the differences in the quality characteristics of yak ghee in different geographical regions. Therefore, it can provide a theoretical basis for the origin tracing and quality-oriented improvement of yak ghee.

Functional and Quality Profile Evaluation of Butters, Spreadable Fats, and Shortenings Available from Czech Market

The aim of this study was to assess the functional properties of butters, spreadable fats, and shortenings, collected from the Czech market, in correlation with their nutritional values declared by the producers. Various methods were applied to determine relevant parameters of the products. Using penetration tests, samples were characterized by specific textural attributes according to their composition and processing type, particularly for the presence of milk/vegetable fats. Using differential scanning calorimetry (DSC), thermal peaks corresponding to medium- and high-melting triacylglycerol fractions were detected in the ranges 15–16 °C and 31.5–34.5 °C, respectively. Rheological analysis revealed that the viscoelasticity of samples was related to frequency behavior of the fat structure, characterized by the dominance of elastic modulus (G′) over viscous modulus (G″) up to the frequency of 10 Hz. This indicated good emulsion stability of the products in the region of linear viscoelasticity. For spreadable fats, the structure was resistant to phase separation in the whole frequency range under study (0.1–100 Hz). The results showed that the applied techniques can be successfully used to characterize the processing and compositional quality of butters and vegetable fats.

Encapsulation of Nutraceuticals in Yoghurt and Beverage Products Using the Ultrasound and High-Pressure Processing Technologies

Dairy and beverage products are considered highly nutritious. The increase demand for added nutritional benefits within the food systems consumed by the consumers paves the pathway towards fortifying nutraceuticals into these products. However, nutraceuticals are highly unstable towards harsh processing conditions. In addition, the safety of dairy and beverage products plays a very important role. Therefore, various heat treatments are in practice. As the heat-treated dairy and beverage products tends to illustrate several alterations in their organoleptic characteristics and nutritional properties, the demand for alternative non-thermal processing technologies has increased extensively within the food industry. Ultrasound and high-pressure processing technologies are desirable for this purpose as well as a safe and non-destructive technology towards encapsulation of nutraceuticals into food systems. There are benefits in implementing these two technologies in the production of dairy and beverage products with encapsulants, such as manufacturing high-quality products with improved nutritional value while simultaneously enhancing the sensory characteristics such as flavour, taste, texture, and colour and attaining the microbial quality. The primary objective of this review is to provide detailed information on the encapsulation of nutraceuticals and mechanisms involved with using US and HPP technologies on producing encapsulated yoghurt and beverage products.

A combined approach for modifying pea protein isolate to greatly improve its solubility and emulsifying stability

Pea protein-based delivery systems have drawn much attention in the food and pharmaceutical fields in recent years. However, its broad application faces great limitations because of the low solubility. Here, we present a novel and effective approach to overcome this difficulty and enhance the techno-functional characteristics, especially emulsifying stability, of the pea protein isolate (PPI). By combining pH-shifting with ultrasound and heating (PUH), we concluded that the solubility of PPI greatly increased from 29.5 % to 90.4 %, whereas its surface hydrophobicity increased from 1098 to 3706. This was accompanied by the changes of PPI structure, as shown by circular dichroism and scanning electron microscopy. In addition, the modified PPI was applied to stabilize sunflower oil-in-water emulsions. The droplet size of the emulsion with PUHP was reduced and its emulsion stability was significantly elevated. Taken together, we propose a novel combined approach to prepare modified PPI with high solubility and emulsion stability. We expect our method will have a wider application in modifying plant proteins and improving their industrial processing.

Positive effects of thermosonication in Jamun fruit dairy dessert processing

The effects of thermosonication processing (TS, 90 °C, ultrasound powers of 200, 400, and 600 W) on the quality parameters of Jamun fruit dairy dessert compared to conventional heating processing (high-temperature short time, (HTST), 90 °C/20 s) were evaluated. Microbiological inactivation and stability, rheological parameters, physical properties, volatile and fatty acid profiles, and bioactive compounds were assessed. TS provided more significant microbial inactivation (1 log CFU mL-1) and higher microbial stability during storage (21 days) than HTST, with 3, 2, and 2.8 log CFU mL-1 lower counts for yeasts and molds, aerobic mesophilic bacteria, and lactic acid bacteria, respectively. In addition, TS-treated samples showed higher anti-hypertensive (>39%), antioxidant (>33%), and anti-diabetic (>27%) activities, a higher concentration of phenolic compounds (>22%), preservation of anthocyanins, and better digestibility due to the smaller fat droplet size (observed by confocal laser scanning microscopy). Furthermore, lower TS powers (200 W) improved the fatty acid (higher monounsaturated and polyunsaturated fatty acid contents, 52.78 and 132.24%) and volatile (higher number of terpenes, n = 5) profiles and decreased the atherogenic index. On the other hand, higher TS powers (600 W) maintained the rheological parameters of the control product and contributed more significantly to the functional properties of the products (antioxidant, anti-hypertensive, and anti-diabetic). In conclusion, TS proved to be efficient in treating Jamun fruit dairy dessert, opening space for new studies to define process parameters and expand TS application in other food matrices.

Recent advances in the application of ultrasound in dairy products: Effect on functional, physical, chemical, microbiological and sensory properties

Alternative methods for improving traditional food processing have increased in the last decades. Additionally, the development of novel dairy products is gaining importance due to an increased consumer demand for palatable, healthy, and minimally processed products. Ultrasonic processing or sonication is a promising alternative technology in the food industry as it has potential to improve the technological and functional properties of milk and dairy products. This review presents a detailed summary of the latest research on the impact of high-intensity ultrasound techniques in dairy processing. It explores the ways in which ultrasound has been employed to enhance milk properties and processes of interest to the dairy industry, such as homogenization, emulsification, yogurt and fermented beverages production, and food safety. Special emphasis has been given to ultrasonic effects on milk components; fermentation and spoilage by microorganisms; and the technological, functional, and sensory properties of dairy foods. Several current and potential applications of ultrasound as a processing technique in milk applications are also discussed in this review.

Low and High-Intensity Ultrasound in Dairy Products: Applications and Effects on Physicochemical and Microbiological Quality

Milk and dairy products have a major role in human nutrition, as they contribute essential nutrients for child development. The nutritional properties of dairy products are maintained despite applying traditional processing techniques. Nowadays, so-called emerging technologies have also been implemented for food manufacture and preservation purposes. Low- and high-intensity ultrasounds are among these technologies. Low-intensity ultrasounds have been used to determine, analyze and characterize the physical characteristics of foods, while high-intensity ultrasounds are applied to accelerate particular biological, physical and chemical processes during food product handling and transformation. The objective of this review is to explain the phenomenology of ultrasounds and to detail the differences between low and high-intensity ultrasounds, as well as to present the advantages and disadvantages of each one in terms of the processing, quality and preservation of milk and dairy products. Additionally, it reviews the rheological, physicochemical and microbiological applications in dairy products, such as raw milk, cream, yogurt, butter, ice cream and cheese. Finally, it explains some methodologies for the generation of emulsions, homogenates, crystallization, etc. Currently, low and high-intensity ultrasounds are an active field of study, and they might be promising tools in the dairy industry.

Effect of storage time on physical properties of sonocrystallized all-purpose shortening

The purpose of this study was to determine the effect of high-intensity ultrasound (HIU) on the physical properties of an all-purpose shortening and to evaluate how these properties changed during storage (48 hr; 4, 12, and 24 weeks) at 5 °C and 25 °C. Samples were crystallized at 30 °C for 60 min with and without the application of HIU (20 kHz; 3.2 mm-diameter tip, 168 µm amplitude, 10 s). After crystallization, physical properties, such as hardness, elasticity, melting behavior, and solid fat content (SFC), were measured. These properties were also measured during storage. The effect of HIU was significant in changing the SFC, hardness, G' and G'', melting enthalpy, and microstructure of the samples. After 60 min of crystallization, the sonicated samples had higher values of SFC, hardness, elasticity, and melting enthalpy than the ones obtained without sonication (P < 0.05). Changes in these physical properties were associated with the microstructure of the samples since sonication generated smaller, more uniformly sized crystals as well as increased the number of crystals. No differences were observed in the G' of the sonicated samples stored at 25 °C as a function of storage period. The G' of the nonsonicated samples increased until 12 weeks of storage and was maintained up to 24 weeks, suggesting that sonication speed up the formation of a stable crystalline network. Samples stored at 5 °C showed higher value in hardness, G' and G'', and SFC than the ones stored at 25 °C. PRACTICAL APPLICATION: High-intensity ultrasound (HIU) has been widely used as an additional tool to change the crystallization behavior in various lipids; however, the long-term storage effect of HIU has not been studied before. This research evaluates the effect of HIU on the physical properties of a palm-based shortening stored up to 24 weeks at two different temperatures (25 and 5 °C). The application of HIU may help increase the stability of lipid during storage.

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 β' and β, 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.

Effect of ultrasound on the techno-functional properties of food components/ingredients: A review

Ultrasound (US) has been used in many food systems and model systems, such as starch, whey protein concentrates and soy, to modify their chemical and techno-functional properties. At present, the use of ultrasound has yielded diverse results, ranging from potentiating the technological and functional properties of various foods to different operating conditions. Similarly, the results that were obtained vary according to the ultrasonic equipment used and the power, frequency and times of sonication, as well as the characteristics of the food system used. However, not all results have been favourable because US can cause damage to the structure of some food components, such as starch, and affect the technological and functional properties of the food. In the literature, there is little research on the effect of sonication on fibre; this gap in the literature is worrisome because fibre is found in a wide variety of foods and provides health benefits. Such research would represent an opportunity for researchers to make use of this technology for the generation of knowledge and improve the techno-functional properties in fibre, which could benefit the human population and the food industry. In this review, we present current results obtained with US in different treatments affecting processes of strong importance in the food industry, emphasizing the effects in the different model systems.

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 β' 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 β', 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.