Development of functional yogurt containing free and encapsulated echium oil, phytosterol and sinapic acid

INVITED REVIEW: Advances in Yogurt Development: Microbiological Safety, Quality, Functionality, Sensory Evaluation, and Consumer Perceptions across Different Dairy and Plant-based Alternative Sources

Yogurt, as a globally prevalent fermented dairy product, is renowned for its substantial nutritional value and a myriad of health benefits, particularly pertaining to the digestive system. This narrative review elucidates the latest advancements in yogurt development from 2019 to 2024, addressing aspects of microbiological safety, quality, functionality, sensory evaluation, and consumer perceptions across diverse protein sources. The intrinsic quality of yogurt is significantly influenced by its primary ingredient, milk, traditionally derived from animals such as cows, goats, and sheep. In recent years, plant-based yogurts (PBYs) have emerged as a popular alternative to traditional dairy yogurts, that are made from plant sources and offer similar textures and flavors, catering to those seeking non-dairy options. This discussion encompasses the advantages and limitations of various sources and explores methodologies to enhance yogurt quality using these diverse sources. Ensuring the microbiological safety of yogurt is thus paramount to its quality, as it involves both preventing the presence of harmful pathogens and managing spoilage to maintain freshness. This article encapsulates the potential hazards and corresponding antibacterial strategies that safeguard yogurt consumption. These strategies include the use of natural preservatives, advancements in packaging technologies, and the implementation of stringent hygiene practices throughout the production process. Morever, the quality of yogurt is not only dependent on the source but also on the fermentation process and additional ingredients used. By addressing both the prevention of pathogen contamination and the control of spoilage organisms, this article explores not only explores comprehensive approaches but also examines the use of high-quality starter cultures, the role of prebiotics in enhancing probiotic efficacy, and genetic advancements, as well as improvements in the overall nutritional profile and shelf life of yogurt. Techniques to improve texture, flavor, and nutrient content are also discussed, providing a comprehensive overview of current quality enhancement methods.This analysis delves into the intricate mechanisms underpinning probiotic development, including the roles of prebiotics, supplementary starter cultures, and genetic factors that facilitate probiotic proliferation. These benefits include improved digestive health, enhanced immune function, and potential reductions in the risk of certain chronic diseases. Beyond quality and functionality, the sensory evaluation of yogurt remains crucial for consumer acceptance. In recent years, the incorporation of diverse additional ingredients into yogurt has been observed, aimed at augmenting its sensory attributes. This examination reveals these ingredients and their respective functions, such as natural flavorings, sweeteners, and texturizing agents, with the ultimate goal of enhancing overall consumer satisfaction. Consumer preferences exert a profound influence on yogurt production, rendering the understanding of customer opinions essential for devising competitive industry strategies. This article consolidates consumer feedback and preferences, striving to elevate yogurt quality and promote dietary diversity. The analysis includes trends such as the growing demand for organic and non-dairy yogurts, the importance of sustainable practices, and the impact of marketing and packaging on consumer choices. This comprehensive overview serves as a valuable reference for the dairy industry and researchers dedicated to the advancement of yogurt development.

Engineering the β-galactosidase from Aspergillus oryzae for making lactose-free and no-sugar-added yogurt

Yogurt usually contains 5% to 7% sugar and 3% to 5% lactose. As β-galactosidases can hydrolyze lactose and improve sweetness, they have the potential to produce lactose-free (LF) and no-sugar-added (NSA) yogurt. In this study, the β-galactosidase AoBgal35A from Aspergillus oryzae was engineered by site-saturation mutagenesis. Results of 19 variants of T955 residue showed that the lactose hydrolysis rate of T955R-AoBgal35A was up to 90.7%, which is much higher than the 78.5% of the wild type. Moreover, the optimal pH of T955R-AoBgal35A was shifted from pH 4.5 to pH 5.5, and the optimal temperature decreased from 60°C to 50°C. The mutant T955R-AoBgal35A was successfully expressed in Komagataella pastoris, which produced extracellularly 4,528 U/mL of β-galactosidase activity. The mutant T955R-AoBgal35A was used to produce LF yogurt. The Streptococcus thermophilus count of LF yogurt increased from 7.9 to 9.5 log cfu/g, which is significantly higher than that of the control group (8.9 log cfu/g). The residual lactose content of LF yogurt was 0.13%, meeting the requirements of the national standard in China for the "lactose-free" label (<0.5%). Furthermore, sugar in yogurt was replaced by whey powder to produce LF-NSA yogurt. The optimal addition content of whey powder was 7.5%. The texture, water-holding capacity, and titratable acidity of LF and LF-NSA yogurt achieved good shelf life stability. Therefore, this study provides an insight for technological implications of β-galactosidases in the dairy industry.

Microencapsulation of flaxseed oil in pea protein-gum arabic complex coacervates delays lipid digestion in liquid yoghurt

Flaxseed oil coacervates were produced by complex coacervation using soluble pea protein and gum arabic as shell materials, followed by either spray or electrostatic spray drying and their incorporation to yoghurt. Three yoghurt formulations were prepared: yoghurt with spray-dried microcapsules (Y-SD); with electrospray-dried microcapsules (Y-ES); with the encapsulation ingredients added in free form (Y). The standardised semi-dynamicin vitrodigestion method (INFOGEST) was employed to study the food digestion. The structure was analysed by confocal laser scanning microscopy and particle size distribution. Protein and lipid digestion were monitored by cumulated protein/free NH2 release and cumulated free fatty acids release, respectively. Stable microcapsules were observed during gastric digestion, but there was no significant difference in protein release/hydrolysis among samples until 55 min of gastric digestion. Formulation Y showed less protein release after 74 min (40.46 %) due to the free SPP being available and positively charged at pH 2-4, resulting in interactions with other constituents of the yoghurt, which delayed its release/hydrolysis. The total release of protein and free NH2 by the end of intestinal digestions ranged between 46.56-61.15 % and 0.83-1.57 µmol/g protein, respectively. A higher release of free fatty acids from formulation Y occurred at the end of intestinal digestion, implying that coacervates promoted the delayed release of encapsulated oil. In summary, incorporating protein-polysaccharides-based coacervates in yoghurt enabled the delay of the digestion of encapsulated lipids but accelerated the digestion of protein, suggesting a promising approach for various food applications.

Delivery of encapsulated bioactive compounds within food matrices to the digestive tract: recent trends and future perspectives

Encapsulation technologies have achieved encouraging results improving the stability, bioaccessibility and absorption of bioactive compounds post-consumption. There is a bulk of published research on the gastrointestinal behavior of encapsulated bioactive food materials alone using in vitro and in vivo digestion models, but an aspect often overlooked is the impact of the food structure, which is much more complex to unravel and still not well understood. This review focuses on discussing the recent findings in the application of encapsulated bioactive components in fabricated food matrices. Studies have suggested that the integration of encapsulated bioactive compounds has been proven to have an impact on the physicochemical characteristics of the finished product in addition to the protective effect of encapsulation on the fortified bioactive compound. These products containing bioactive compounds undergo further structural reorganization during digestion, impacting the release and emptying rates of fortified bioactive compounds. Thus, by manipulation of various food structures and matrices, the release and delivery of these bioactive compounds can be altered. This knowledge provides new opportunities for designing specialized foods for specific populations.

Enrichment of a fruit-based smoothie beverage with omega-3 fatty acids from microencapsulated chia seed oil

BACKGROUND

Omega-3 fatty acids are known for their various health benefits. Chia is the richest vegetable source of omega-3 fatty acids. However, its oil is highly susceptible to oxidative deterioration and should be protected for incorporation into food matrices. This work aimed to study the incorporation of different chia oil microcapsules in a powdered beverage, analyzing the effect on the physicochemical characteristics and stability during storage.

RESULTS

Different types of microcapsules were obtained: monolayer microcapsules using sodium caseinate and lactose as wall material, and multilayer microcapsules produced through electrostatic deposition using lecithins, chitosan, and chia mucilage as the first, second, and third layers, respectively. The results demonstrated an efficient enrichment of smoothies, with omega-3 fatty acid values ranging from 24.09% to 42.73%, while the original food matrix powder lacked this component. These powder beverages exhibited low moisture content (≤ 2.91%) and low water activity (≤ 0.39). The aerated, packed density and compressibility assays indicated that adding microcapsules made the powders less dense and compressible. The color of the original powdered beverage was not modified. The dispersibility reflected an acceptable instantaneity, reaching the maximum obscuration after 30 s of stirring. The solubility of all the enriched products was higher than 70%, whereas the pH was ~6.8. The contact angle between the powder and liquid indicated an excellent ability to be reconstituted in water. The analysis of the glass transition temperature showed that the storage temperature (25 °C) was adequate. The peroxide value of all the products was low throughout the storage (≤ 1.63 meq peroxide kg-1 of oil at 90 days at 25 ± 2 °C), thus maintaining the quality of the microencapsulated chia oil.

CONCLUSIONS

The results suggest that incorporating the monolayer and multilayer chia oil microcapsules that were studied could be a viable strategy for enriching smoothies with the omega-3 fatty acids present in chia seed oil. © 2023 Society of Chemical Industry.

Microfluidization improved hempseed yogurt's physicochemical and storage properties

BACKGROUND

Plant-based yogurts are suffering from the common problems, such as an unattractive color, stratified texture state and rough taste. Therefore, it is urgent to develop a novel processing method to improve the quality and extend the storage life of hempseed yogurt. In the present study, hempseed yogurt was microfluidized prior to fermentation. The effects of microfluidization on microstructure, particle size, mechanical properties, sensory acceptability, variations in pH and titratable acidity, lactic acid bacteria (LAB) counts, and stability of hempseed yogurt during 20 days of storage were investigated.

RESULTS

Microfluidization contributed to the production of hempseed yogurt as a result of the better physicochemical properties compared to normal homogenization. Specifically, microfluidization reduced the particle size of hempseed yogurt with a uniform particle distribution, increased water holding capacity, and improved texture and rheological properties. These advancements resulted in higher sensory scores for the yogurt. Furthermore, during storage, microfluidization effectively inhibited the post-acidification process of hempseed yogurt, and increased LAB counts and storage stability.

CONCLUSION

Microfluidization improved the physicochemical properties and storage stability of hempseed yogurt. Our findings support the application of microfluidization in hempseed yogurt and provide a new approach for enhancing the quality of plant-based alternatives that meet consumers' demands for high-quality food products. © 2023 Society of Chemical Industry.

Enrichment of set yoghurt with flaxseed oil, flaxseed mucilage and free or encapsulated Lacticaseibacillus casei: Effect on probiotic survival and yoghurt quality attributes

This study was intended to develop yoghurt products incorporated with flaxseed mucilage (FM), flaxseed oil (FO) and free or encapsulated Lacticaseibacillus casei probiotics. FM (0.9%) and sodium alginate (2%) were used as wall materials for encapsulating L. casei. Different physicochemical and sensory properties of the yoghurt, as well as the L. casei survival, were determined during 21 days of storage at 4 °C. Based on the results, FM showed a stimulatory effect on the growth of probiotics and thus, significantly decreased the Log reduction of the probiotics during storage (P < 0.05). Moreover, encapsulating probiotics significantly decreased the Log reduction during storage in comparison with the free bacteria (P < 0.05). Incorporating FM and free probiotics significantly increased the acidity and decreased the pH of the samples; while encapsulating L. casei successfully prevented the acidity increment in probiotic fortified yoghurt products (P < 0.05). The addition of FM significantly improved the water holding capacity of the yoghurt (P < 0.05). Incorporating either free L. casei, FO or FM significantly reduced the flavor and overall acceptance scores; while, the addition of L. casei in the encapsulated form did not significantly alter the overall acceptance scores of the yoghurt samples (P < 0.05).

Current and New Insights on Delivery Systems for Plant Sterols in Food

Plant sterols are minor bioactive components of food lipids, which are often used for the formulation of functional foods due to their cholesterol-lowering properties. However, they have low solubility and tend to crystallize, which may affect their biological effects, the sensory profile of the sterol-enriched food, and its consumer acceptability. Moreover, due to the unsaturated structure of sterols, they are susceptible to oxidation, so different encapsulation systems have been developed to improve their dispersibility/solubility, stability, delivery, and bioaccessibility. This chapter provides an overview of the main encapsulation systems currently used for plant sterols and their application in model and food systems, with a particular focus on their efficiency and impact on sterol bioaccessibility.

An Innovative Method for the Production of Yoghurt Fortified with Walnut Oil Nanocapsules and Characteristics of Functional Properties in Relation to Conventional Yoghurts

Polyunsaturated fatty acids (PUFAs) are crucial nutrients involved in a plethora of metabolic and physiological processes. PUFAs have been extensively researched for their effects on human nutrition and health. The high demand for these fatty acids offers the possibility of adding vegetable oils to dairy products such as yoghurt. The aim of this study was to produce nano/microcapsules comprising walnut oil through exclusively natural ingredients utilised in yoghurt manufacturing. Additionally, the study tested yoghurt supplemented with PUFAs using the acquired nano/microcapsules. Chemical and physiochemical properties, microbiological analysis, rheological measurements, texture analysis, scanning electron microscope (SEM) analysis, ATR-FTIR spectroscopy, and sensory and fatty acids profile analysis were performed. A physico-chemical analysis highlighted the impact of oil addition on fat and dry matter concentration, revealing an increased quantity of said components in yoghurt after oil addition. Based on the identified parameters for potential and active acidity in the yoghurts, normal lactic fermentation was observed. Furthermore, the addition of oil was found to have an impact on the pH of the yoghurt. Microbiological analysis indicated that the incorporation of nano-encapsulated walnut oil did not have any notable effect on the abundance of determined microorganisms in the yoghurt. However, it was observed that the number of Lactobacillus delbrueckii ssp. bulgaricus increased as a result of storage. The incorporation of enclosed oil in yoghurt resulted in negligible alterations in rheological and sensory characteristics when compared with the plain variant. The addition of oil had an effect on most of the analysed fatty acids. Fortified yoghurt shows a more favourable proportion of the fatty acid groups tested (SFA, MUFA, and PUFA) and lower values of fat quality factors (AI and TI).

Functional stirred yogurt manufactured using co-microencapsulated or free forms of grape pomace and flaxseed oil as bioactive ingredients: Physicochemical, antioxidant, rheological, microstructural, and sensory properties

Functional stirred yogurt samples were manufactured with combinations of grape pomace (GP) and flaxseed oil (FO) in microencapsulated or free forms (2% w/w) and quality characteristics of yogurts were investigated during 21 days of storage. The incorporation of GP and FO in microencapsulated or free forms caused a significant decrease in pH, syneresis, and a significant increase in acidity, water holding capacity, and viscosity of stirred yogurt (p < .05). While stirred yogurt containing GP and FO in free form had the highest loss modulus (G″), all yogurt samples represented solid-like behavior. Stirred yogurts containing the microencapsulated form of GP and FO showed the highest amount of phenolics and antioxidant activity compared with the two other yogurt samples (p < .05). More compact structure and higher gel strength were observed in stirred yogurts formulated with the microencapsulated or free form of GP and FO, compared to the control yogurt sample. The overall sensory acceptability of stirred yogurt manufactured using the encapsulated form of GP and FO was not significantly different from the control yogurt sample (p > .05). In conclusion of this competitive study, GP and FO as bioactive compounds could be used in the microencapsulated form in order to develop functional stirred yogurt with specific quality characteristics.

Incorporation of Solid Lipid Nanoparticles into Stirred Yogurt: Effects in Physicochemical and Rheological Properties during Shelf-Life

The aim of this work was to develop a yogurt fortified with curcumin. Curcumin is a lipophilic compound with a wide range of biological activities; however, it presents low water solubility and low bioavailability, and therefore it was the first to be encapsulated in solid lipid nanoparticles (SLNs). Then the influence of the incorporation of curcumin-loaded SLNs on the physicochemical (i.e., pH, titratable acidity, syneresis and color) and rheological properties of yogurt during its shelf-life (30 days at 4 °C) was evaluated. SLN incorporation into yogurt did not affect pH and titratable acidity compared to the control (i.e., plain yogurt) during shelf-life, even though the yogurt with SLNs presented lower values of pH (4.25 and 4.34) and acidity (0.74% lactic acid and 0.84% lactic acid) than the control in the end, respectively. Furthermore, the yogurt with SLNs presented slightly higher values of syneresis than the control during the shelf-life; however, it did not present visual differences in whey separation. Relative to the color, the incorporation of SLNs into the yogurt imparted a strong yellow color to the sample but did not affect color stability during shelf-life. Both samples showed flow curves with yield stress and shear-thinning behavior during shelf-life, and, regarding the viscoelastic behavior, both showed a typical weak viscoelastic gel with an elastic structure. Overall, curcumin-loaded SLNs incorporation did not affect the physicochemical and rheological stability of yogurt during shelf-life, showing a promising application for the development of new functional foods.

Utilization of durian seed for Monascus fermentation and its application as a functional ingredient in yogurt

As a widely consumed fermented milk product, yogurt undergoes constant development to increase its functional properties. Monascus purpureus-fermented durian seed, which has been proven to possess antioxidative properties, has the potential to improve yogurt properties. This study aimed to analyze the use of Monascus-fermented durian seed (MFDS) as a functional ingredient in yogurt and its effect on physicochemical properties, lactic acid bacteria (LAB) count, antioxidative properties, and consumer acceptability of set-type yogurt during refrigeration. Changes in physicochemical properties, including color, pH, titratable acidity, syneresis, LAB count, total phenolic content (TPC), and antioxidant activity were evaluated at 7-day intervals during 14 days of refrigerated storage (4 °C). Sensory evaluations were carried out for freshly made samples after 7 days of storage. The results showed that the addition of MFDS to yogurt gave significant effects on some of the parameters measured. Yogurt with added MFDS powder produced a more red color (L = 88.55 ± 1.28, a* = 2.63 ± 0.17, b* = 11.45 ± 1.15, c = 11.75 ± 1.15, H = 77.00 ± 0.64), reached the highest TPC (2.21 ± 0.46 mg/GAE g), antioxidant activity (0.0125 ± 0.0032 mg GAE/g), and syneresis (5.24 ± 0.51%) throughout 14 days of storage. The addition of MFDS only gave a slight difference to pH and titratable acidity, while no significant difference was made for LAB count. For sensory evaluation, the addition of MFDS, particularly the ethanol extract, to yogurt was well-liked by panelists. Citrinin content in MFDS yogurt can be decreased under the limits set. Overall, the addition of MFDS has a high potential of improving yogurt properties, particularly its antioxidative properties.

Reasonableness of Enriching Cow’s Milk with Vitamins and Minerals

Milk is an exceptional nutritional product that has been used for many millennia in human nutrition. Milk is a source of many valuable nutrients, including calcium, vitamin B, an especially significant amount of vitamin B2 and fat-soluble vitamins, such as A, D and E. Milk is an attractive product for fortification as it has a high nutritional density in a small volume and a relatively low price. Research shows positive health effects of drinking milk and consuming dairy products. Even more health benefits can be obtained from consuming fortified dairy products. A literature review, current nutritional recommendations, medical recommendations and an analysis of the market situation all recommend introducing milk enriched with minerals in combination with vitamins to the market. This concept corresponds to the current market demand and may supplement the missing and expected range of fortified milk and the correct number of recipients.

Encapsulation of Different Types of Probiotic Bacteria within Conventional/Multilayer Emulsion and Its Effect on the Properties of Probiotic Yogurt

Microencapsulation of probiotic cells within emulsion is an efficient method to enhance the viability of probiotic bacteria. In the present study, free and encapsulated probiotic cells (Lactobacillus rhamnosus and Lactobacillus plantarum) in simple and multilayer emulsions were used to produce a set of probiotic yogurts. In all samples, an increasing trend in syneresis and acidity values and a decreasing trend in pH and viability of probiotic cells were observed during the storage time. However, the changes in these parameters were more significant for free-loaded probiotic samples. Moreover, the free cells showed poor survival in the yogurt samples by decreasing the viable cell count of probiotics from 7.71–7.59 logs CFU/mL to 6.93–6.82 log CFU/mL during storage, while encapsulation in the multilayer emulsion showed an insignificant reduction from 7.65–7.59 logs CFU/mL to 7.55–7.45 log CFU/mL at the end of storage. The obtained results showed that the type of probiotic bacteria had no significant effects on the physicochemical and structural properties of samples. However, encapsulating probiotics in multilayer emulsion led to a more homogenous structure in yogurt. The sensorial properties were also not affected by the probiotic type and the encapsulation method. Consequently, the multilayer emulsion can provide an ideal delivery carrier for encapsulating probiotic bacteria in dairy products.

Impact of storage on the functional characteristics of a fermented cereal product with probiotic potential, containing fruits and phytosterols

The aim of this work was to study the changes in the functional characteristics of a fermented maize product containing fruits, and enriched with phytosterols. Functional characteristics (natural antioxidants and phytosterols content, in vitro antioxidant capacity and probiotic viability), lipid oxidation, and physicochemical parameters were investigated during 4 weeks of storage at 4 °C. The differences between one formulation elaborated with semi-skimmed powdered milk (Basic Product) and another with whey protein isolate (WPI Product) were evaluated. The content of polyphenols, carotenoids and tocopherols remained unchanged during the storage of both formulations. These compounds increased the antioxidant capacity in both products compared to the control formulation (without fruits), which was displayed along the whole storage period. The doses of phytosterols and the probiotic potential were maintained to the end of the storage period for both formulations. Basic and WPI products represent novel foods with desirable functional characteristics preserved during commercial storage.

Prospective Study on Microencapsulation of Oils and Its Application in Foodstuffs

BACKGROUND

Edible oils have gained the interest of several industrial sectors for the different health benefits they offer, such as the supply of bioactive compounds and essential fatty acids. Microencapsulation is one of the techniques that has been adopted by industries to minimize the degradation of oils, facilitating their processing.

OBJECTIVE

To evaluate the intellectual property related to patent documents referring to microencapsulated oils used in foods.

METHODS

This prospective study investigated the dynamics of patents filed in the Espacenet and National Institute of Industrial Property (INPI) databases, and it mapped technological developments in microencapsulation in comparison with scientific literature.

RESULTS

The years 2015 and 2018 showed the greatest growth in the number of patents filed in the Espacenet and INPI databases, respectively, with China leading the domains of origin, inventors, and owners of microencapsulation technology. The largest number of applications of microcapsules were observed in the food industry, and the foods containing microencapsulated oils were powdered seasonings, dairy products, rice flour, nutritional formulae, pasta, nutritional supplements, and bread. The increase in oxidative stabilities of oils was the most cited objective to microencapsulate oils. Spray drying was the most widely used microencapsulation technique, and maltodextrin, gum arabic, and modified starch were the most widely used wall materials.

CONCLUSION

Microencapsulation of oils has been expanding over the years and increasing the possibilities of the use of microcapsules, but further investments and development of policies and incentive programs to boost this technology need to be made in less developed countries. For future perspectives, the microencapsulation technique is already a worldwide trend in the food industry, enabling the development of new products to facilitate their insertion in the consumer market.

Development of natural pigments microencapsulated in waste yeast Saccharomyces cerevisiae using spray drying technology and their application in yogurt

Although Saccharomyces cerevisiae has shown potential utilization as a bio-vehicle for encapsulation, there are no reports about the functionality of natural colorants encapsulated using yeast cells. The main objectives of this study were to produce natural food coloring by encapsulating extracts from grape pomace (GP) and jabuticaba byproducts (JB) in brewery waste yeast and evaluate the functionality of the pigments by their incorporation into yogurts. Particles produced by the encapsulation of extracts from GP and JB in S. cerevisiae using 5% of yeast had the highest encapsulation efficiencies for both anthocyanins (11.1 and 47.3%) and phenolic compounds (67.5 and 63.6%), the highest concentration of both bioactives during storage and stable luminosity. Yogurts showed a pseudoplastic behavior and were considered weak gels. Colored yogurts had acceptance indexes between 73.9 and 81.4%. This work evidenced the utilization of enriched yeasts as coloring agents and interesting additives for the production of functional foods.

Microencapsulation of Bioactive Ingredients for Their Delivery into Fermented Milk Products: A Review

The popularity and consumption of fermented milk products are growing. On the other hand, consumers are interested in health-promoting and functional foods. Fermented milk products are an excellent matrix for the incorporation of bioactive ingredients, making them functional foods. To overcome the instability or low solubility of many bioactive ingredients under various environmental conditions, the encapsulation approach was developed. This review analyzes the fortification of three fermented milk products, i.e., yogurt, cheese, and kefir with bioactive ingredients. The encapsulation methods and techniques alongside the encapsulant materials for carotenoids, phenolic compounds, omega-3, probiotics, and other micronutrients are discussed. The effect of encapsulation on the properties of bioactive ingredients themselves and on textural and sensory properties of fermented milk products is also presented.

Twenty-five years of total antioxidant capacity measurement of foods and biological fluids: merits and limitations

This review summarises 25 years of investigations on antioxidants research in foods and biological fluids and critically analyses the merits and limitations of using the total antioxidant capacity (TAC) measurement in the metabolomic era. An enormous bulk of knowledge was produced regarding the antioxidant capacity of foods and large TAC databases were developed. A direct link between a food TAC value and any health benefit is erroneous and has led to several cases of consumer deception. However, the striking epidemiological evidence associating a high dietary TAC with some disease prevention and the availability of well-constructed TAC databases deserve attention and must be taken into account to establish the usefulness of measuring TAC in both foods and biological samples. The in vivo TAC measurement, usually performed in plasma, is influenced by many external factors, such as dietary habits, as well as environmental and behavioural factors, which are integrated towards homeostatic control by fine physiological mechanisms with high inter-individual variability. Therefore, plasma TAC cannot be considered as a unique biomarker of individual antioxidant status. However, the combined evaluation of plasma TAC with known markers of disease, individual metabolism, inflammation and genetics, as well as with markers of gut microbiota composition and activity, may lead to the identification of populations that are more responsive to food/diet TAC. In this framework, the appropriate use of TAC measurement both in food and in vivo can still provide support for the interpretation of complex phenomena and be a tool for sample screening when making a quick decision toward in-depth research investigations. © 2018 Society of Chemical Industry.

How unsaturated fatty acids and plant stanols affect sterols plasma level and cellular membranes? Review on model studies involving the Langmuir monolayer technique

The Langmuir monolayer technique has long been known for its usefulness to study the interaction between molecules and mimic cellular membranes to understand the mechanism of action of biologically relevant molecules. In this review we summarize the results that provided insight into the potential mechanism for lowering the plasma level of cholesterol by hypocholesterolemic substances (unsaturated fatty acids (UFAs) and phytocompounds) - in the aspect of prevention of atherosclerosis - and their effects on model biomembranes. The results on UFAs/cholesterol (oxysterols) interactions indicate that these systems are miscible and strongly interacting, contrary to immiscible systems containing saturated fatty acids. Lowering of cholesterol plasma level by UFAs was attributed to the strong affinity between UFAs and sterols, resulting in the formation of high stability complexes, in which sterols were bound and eliminated from the body. Studies on the effect of UFAs and plant sterols/stanols on simplified biomembranes (modeled as cholesterol/DPPC system) indicated that the studied hypocholesterolemic substances modify the biophysical properties of model membrane, affecting its fluidity and interactions between membrane components. Both UFAs and plant sterols/stanols were found to loosen interactions between DPPC and cholesterol and decrease membrane rigidity caused by the excess cholesterol in biomembrane, thus compensating strong condensing effect of cholesterol and restoring proper membrane fluidity, which is of utmost importance for normal cells functioning. The agreement between model - in vitro - studies and biological results prove the usefulness of the Langmuir monolayer technique, which helps in understanding the mode of action of biologically relevant substances.

Utilization of grape pomaces and brewery waste Saccharomyces cerevisiae for the production of bio-based microencapsulated pigments

This research approaches the utilization of brewery waste yeast Saccharomyces cerevisiae as a vehicle for the encapsulation and protection of phenolic compounds from Cabernet Sauvignon and Bordeaux grape pomace extracts. The main purpose of this research was to enrich the biomass of yeast to investigate its potential as a novel vehicle for further application as pigment or functional ingredient. The obtained powders presented characteristics appropriated for storage, such as low water activity (<0.289), hygroscopicity (<13.71 g/100 g) and moisture (<7.10%) and particle sizes lower than the sensory perceptible (<11.45 µm). This work proved that yeasts were loaded after spray-drying, thus, they might be considered as biocapsules. Furthermore, the bioaccessibility of encapsulated phenolic compounds from Bordeaux and Cabernet Sauvignon extracts was 34.96% and 14.25% higher compared to their respective free extracts, proving that yeasts are not only biocapsules of easy application, but also a biological material capable of protecting and delivering the compounds during gastrointestinal digestion.

Microencapsulation as a Tool for the Formulation of Functional Foods: The Phytosterols' Case Study

Hypercholesterolemia, which is an increase in total and low-density lipoprotein (LDL) serum cholesterol, is an important risk factor for the development of cardiovascular diseases. Lifestyle modifications underpin any action plan for reducing serum cholesterol. Phytosterols are natural compounds belonging to the triterpenes family. Thanks to their structural analogy with cholesterol, phytosterols have the ability to reduce serum LDL-cholesterol levels. Phytosterols are used to enrich or fortify a broad spectrum of food products. Like unsaturated fatty acids and cholesterol, phytosterols are easily oxidized. Microencapsulation could be a useful tool to overcome this and other drawbacks linked to the use of phytosterols in food fortification. In this review, in addition to explaining the phytosterols’ mechanisms of action, a focus on the use of free and encapsulated phytosterols for the formulation of functional foods, taking also into account both technological and legislative issues, is given.

Functional Foods: Product Development, Technological Trends, Efficacy Testing, and Safety

Functional foods is a very popular term in the social and scientific media; consequently, food producers have invested resources in the development of processed foods that may provide added functional benefits to consumers' well-being. Because of intrinsic regulation and end-of-use purposes in different countries, worldwide meanings and definitions of this term are still unclear. Hence, here we standardize this definition and propose a guideline to attest that some ingredients or foods truly deserve this special designation. Furthermore, focus is directed at the most recent studies and practical guidelines that can be used to develop and test the efficacy of potentially functional foods and ingredients. The most widespread functional ingredients, such as polyunsaturated fatty acids (PUFAs), probiotics/prebiotics/synbiotics, and antioxidants, and their technological means of delivery in food products are described. The review discusses the steps that food companies should take to ensure that their developed food product is truly functional.

Sugarcane Juice with Co-encapsulated Bifidobacterium animalis subsp. lactis BLC1 and Proanthocyanidin-Rich Cinnamon Extract

Bioactive compounds are sensitive to many factors, and they can alter the sensory characteristics of foods. Microencapsulation could be a tool to provide protection and allow the addition of bioactives in new matrices, such as sugarcane juice. This study focused on producing and evaluating the potential function of probiotics and proanthocyanidin-rich cinnamon extract (PRCE), both in free and encapsulated forms when added to sugarcane juice. The pure sugarcane juice treatment T1 was compared with other sugarcane juices to which bioactive compounds had been added; T2, a non-encapsulated Bifidobacterium animalis subsp. lactis (BLC1); T3, a non-encapsulated BLC1 and PRCE; T4, BLC1 microcapsules; and T5, with BLC1 and PRCE microcapsules. The samples were morphologically, physicochemically, rheologically, and sensorially characterized. Samples were also evaluated regarding the viability of BLC1 during the juice's storage at 4 °C. It was possible to produce probiotic sugarcane juice with non-encapsulated BLC1, but not with the addition of free PRCE, which in its free form reduced the viability of this microorganism to < 1 log CFU/mL after 7 days. The microcapsules were effective to protect BLC1 during juice storage and to maintain high contents of phenolic and proanthocyanidin compounds, although the products containing these had their viscosity altered and were less accepted than either the control or those with non-encapsulated BLC1.

Multiscale design of a dairy beverage model composed of Candida utilis single cell protein supplemented with oleic acid

One of the main challenges in the food industry is to design strategies for the successful incorporation of natural sources of bioactive compounds. Recently, yogurts and other fermented dairy beverages have been proposed as ideal carriers of such bioactive compounds such as fatty acids and antioxidants that could improve consumers' health. However, the incorporation of new ingredients causes functional and structural modifications that may affect the consumers' preferences. In this work, a dairy beverage model supplemented with oleic acid has been designed by partial substitution of milk by Candida utilis single-cell protein extract. The changes in the structural properties of this new beverage were evaluated by following the fermentation process, pH, aggregate size, microstructure, and changes in rheological properties. Furthermore, molecular dynamics simulations were carried out to analyze the interaction between its main components. Our data revealed that samples with a percentage of milk substitution of 30% showed a higher viscosity as compared with the other percentages and less viscosity than the control (no substitution). These samples were then selected for fortification by incorporating oleic acid microcapsules. A concentration of 1.5 g/100 g was shown to be the optimal quantity of microcapsules for oleic acid supplementation. Molecular dynamic simulations revealed glutathione as an important component of the micro-gel structure. The present study forms the basis for novel studies where Candida utilis single-cell protein and microencapsulated essential oils could be used to design innovative bioproducts.

Incorporation of zeaxanthin nanoparticles in yogurt: Influence on physicochemical properties, carotenoid stability and sensory analysis

Zeaxanthin nanoparticles (Zea-NP) and zeaxanthin nanoemulsion (Zea-NE) were incorporated in yogurt. Control yogurt (CY), yogurt added of nanoparticles (Y-NP) and yogurt added of nanoemulsion (Y-NE) were evaluated weekly regarding pH, titratable acidity, color, textural parameters, viscosity and syneresis during 28 days. Zeaxanthin retention in Y-NP and Y-NE was also determined over storage. Sensory attributes and morphology were evaluated in all yogurt samples, and zeaxanthin bioaccessibility after in vitro digestion was analyzed in Y-NP and Y-NE after preparation. At the end of storage time, zeaxanthin retention was higher in Y-NP (22.31 ± 2.53%) than in Y-NE (16.84 ± 0.53%). Despite the lower firmness and viscosity observed in Y-NP, these changes were not sensory perceived. The bioaccessibility after in vitro digestion suggested that nanoencapsulation provided a controlled release of the carotenoid. Zea-NP can be incorporated in yogurt, allowing the dispersion of a hydrophobic compound in a hydrophilic matrix, providing stability.

Production of probiotic kefir fortified with encapsulated structured lipids and investigation of matrix effects by means of oxidation and in vitro digestion studies

The aim of the present study is to encapsulate structured lipids (SLs) by complex coacervation of gelatin and gum arabic with or without using transglutaminase enzymes and to develop a functional kefir product via the addition of encapsulated SLs in the form of suspension and freeze-dried coacervates. Encapsulated SLs were evaluated for their oxidative stability during 30 days of cold storage. The data showed that coacervate solutions were more sensitive to lipid oxidation compared to freeze-dried capsules. Traditionally produced kefir samples that were fortified with complex coacervation products were stored for 10 days at 4 °C. The pH values of the samples decreased, whereas titratable acidity consistently increased during the storage period. Moreover, an in vitro controlled release study was conducted with a fortified kefir sample containing freeze-dried capsules. According to the results, kefir had no significant matrix effect on oil release from the freeze-dried capsules (p > 0.05).

Effect of natural antioxidants on the physicochemical properties and stability of freeze-dried microencapsulated chia seed oil

BACKGROUND

Chia oil possesses a very high content of polyunsaturated fatty acids, mainly α-linolenic acid. This characteristic makes this oil possess beneficial properties to health but gives it a high susceptibility to the oxidation process. Microencapsulation and the addition of natural antioxidants are alternatives to protect chia oil against oxidative deterioration. The aim of this study was to investigate the physicochemical characteristics and the oxidative stability of chia seed oil microencapsulated with different natural antioxidants (Guardian Chelox, which is a commercial blend of extracts from chamomile and rosemary, and essential oils from Origanum vulgare, Origanum x majoricum, and Mentha spicata) by freeze-drying using sodium caseinate and lactose as wall materials.

RESULTS

The main physicochemical properties of the microencapsulated chia oil were similar regardless of the presence of antioxidant. The moisture content was 38.1 ± 4.0 g kg^-1 ; the microencapsulation efficiency was higher than 85% in all cases. The freeze-drying microencapsulation significantly enhanced (P ≤ 0.05) the oxidative stability of the chia oil. The addition of natural antioxidants conferred chia oil additional protection against lipid oxidation, depending on the type and concentration (500 or 1000 mg kg^-1 of the emulsion previous to freeze-drying) of the antioxidant. Among them, Guardian Chelox (1000 mg kg^-1 ), presented the highest induction time obtained by the Rancimat accelerated oxidative stability test and the lowest peroxide values after 90 days of storage (33% relative humidity, 25 ± 2 °C). Overall, the microparticles with antioxidants presented a lower degree of yellowing during storage than the control system.

CONCLUSION

The use of different natural antioxidants confers freeze-dried microencapsulated chia seed oil additional protection against lipid oxidation. This information is relevant for the application of this oil, which is a rich source of omega-3 fatty acids, in the food industry. © 2018 Society of Chemical Industry.

Non destructive monitoring of the yoghurt fermentation phase by an image analysis of laser-diffraction patterns: Characterization of cow's, goat's and sheep's milk

Monitoring yogurt fermentation by the image analysis of diffraction patterns generated by the laser-milk interaction was explored. Cow's, goat's and sheep's milks were tested. Destructive physico-chemical analyses were done after capturing images during the processes to study the relationships between data blocks. Information from images was explored by applying a spectral phasor from which regions of interest were determined in each image channel. The histograms of frequencies from each region were extracted, which showed evolution according to textural modifications. Examining the image data by multivariate analyses allowed us to know that the captured variance from the diffraction patterns affected both milk type and texture changes. When regression studies were performed to model the physico-chemical parameters, satisfactory quantifications were obtained (from R² = 0.82 to 0.99) for each milk type and for a hybrid model that included them all. This proved that the studied patterns had a common fraction of variance during this processing, independently of milk type.

Echium oil with oxidative stability increased by emulsion preparation in the presence of the phenolic compound sinapic acid followed by dehydration by spray and freeze drying processes

Echium oil is rich in omega-3, however, is unstable. The objective of this work was the co-encapsulation of echium oil and sinapic acid (SA) by emulsification using Arabic gum as emulsifier/carrier, followed by spray or freeze-drying. Eight treatments (S0, S200, S600 and S1000: particles spray dried with different concentrations of SA; L0, L200, L600 and L1000: particles freeze dried with different concentrations of SA) were analyzed in relation to microscopy, water activity (Aw), hygroscopicity, moisture, solubility, particle size, X-ray diffraction, thermogravimetry and accelerated oxidation. Particles of rounded shape and undefined form were obtained by spray and freeze-drying, besides ideal physicochemical properties for application (values from 0.091 to 0.365, 3.22 to 4.89%, 57 to 68% and 2.32 to 12.42 µm for Aw, moisture, solubility and particle size, respectively). All treatments protected the oil against oxidation, obtaining induction time of 5.31 h for oil and from 7.88 to 12.94 h for treatments. The better protection to oil was obtained with it emulsified and freeze-dried (L600); the encapsulation increased oxidative stability of the oil, besides facilitating its application over the fact the material is in powder form.