Physical properties of a frozen yogurt fortified with a nano-emulsion containing purple rice bran oil

Influence of Hesperidin on the Physico-Chemical, Microbiological and Sensory Characteristics of Frozen Yogurt

Frozen yogurts contain yogurt culture bacteria, which might impart health benefits to their consumers. Global frozen yogurt market sales are expected to grow by 4.8% by 2028, which represents an important opportunity for the industry, consumers and researchers. Polyphenols are metabolites found in plants which have antioxidant and anti-inflammatory properties and might prevent chronic diseases such as cancer, diabetes and cardiovascular diseases. The objective of this study was to elucidate the effect of the polyphenol hesperidin on the physico-chemical, microbiological and sensory characteristics of frozen yogurts. Hesperidin was incorporated into frozen yogurt at three concentrations (125, 250 and 500 mg/90 g of product), while yogurt with no hesperidin was used as a control. The viscosity and overrun of the frozen yogurt were analyzed on day 0. The hardness, pH, color and Lactobacillus bulgaricus and Streptococcus thermophilus counts were determined after 0, 30 and 60 d. The melting rate was determined at 60 and 90 min after 0, 30 and 60 d. The bile and acid tolerances of both S. thermophilus and L. bulgaricus were measured after 7 and 60 d. A hedonic scale of nine points was used to measure sensory attributes. Data were analyzed at α = 0.05 with an ANOVA with Tukey's adjustment, and McNemar's test was used to analyze purchase intent. Hesperidin did not influence the pH, overrun or microbial characteristics. Polyphenol addition compared to the control decreased the melting rate but increased the hardness and bile tolerance of L. bulgaricus, as well as the L* and b* values. The sensory characteristics were not influenced by the lowest concentration of hesperidin, as it was not statistically different from the control. Moreover, consumers were interested in purchasing frozen yogurt with added hesperidin after learning about the health claim. This study can assist in the development of a healthier frozen yogurt in an increasingly competitive market.

Production of bioactive and functional frozen yogurt through easy-to-make microspheres incorporation

In the food industry, the microencapsulation process is important to control the release of active encapsulated ingredients, mask unwanted flavors, colors, and unpleasant smells, increase shelf life, and protect encapsulated components from light, moisture, and nutritional loss. In this process, microspheres are formed using cross-linked polymer, which can incorporate aqueous or oily ingredients, using simple physicochemical methods of phase separation by coacervation, without the need for organic solvents. In this context, this study aimed to develop bioactive, functional frozen yogurt through the incorporation of microspheres loaded with ascorbic acid or omega 3. The process used resulted in small microspheres (15-80 μm), imperceptible to the palate, and capable of swelling about 14 times, being suitable for incorporating omega 3, without altering the swelling, and extending the shelf life of the ascorbic acid for 6 weeks, even in an acid medium. Also, the matrix does not affect the properties of frozen yogurt and acts as a stabilizer, contributing to reduce the melting rate. The sensory analysis proved that encapsulation was promising to mask the taste and odor of omega 3 and to protect the ascorbic acid, without altering the properties and quality of the frozen product.

Quality evaluation and storage test for capsaicin-fortified yogurt based on the multilayer nanoemulsion system

Capsaicin has many benefits, such as pain relief, cancer prevention, and weight reduction. However, the application of capsaicin has been limited in the food industry due to its strong pungency, odor, and low solubility in water. Therefore, a multilayer nanoemulsion with chitosan and hyaluronic acid was developed for masking its odor and taste and improving the physicochemical stability against the surrounding environment. The capsaicin-fortified yogurts were prepared by blending various concentration levels of multilayer nanoemulsion (0-15%, w/v). The quality of yogurt was determined as a function of pH, acidity, viscosity, and total lactic acid bacteria population in an extended storage period (21 days). The multivariate statistical analysis was used to compare the quality of yogurts supplemented with capsaicin nanoemulsion. As a result, this study demonstrated the potential of capsaicin-loaded multilayer emulsion-supplemented yogurt as a novel nutrition-fortified food.

Physicochemical properties of rice bran blended oil in deep frying by principal component analysis

This study aimed to obtain a rice bran blended oil with good quality in deep frying. The thermal stability, nutrients and harmful substances of rice bran oil (RBO) and other four oils (palm oil, PO; cottonseed oil, CO; sunflower oil, SuO; soybean oil, SO) were analyzed. Besides, the blended oil formulas were established by the principal component analysis method, and their physicochemical properties, frying characteristic indicators, nutrients, and harmful substances were compared. The results provided that two suitable blended oil formulas (F1: 50% RBO + 40% PO + 10% CO; F2: 60% RBO + 35% PO + 5% CO) of good frying performance were attained by principal component analysis. The acid value (1.19 mg/g), peroxide value (0.09 meq/kg), residual oil rate (8.07%), 3-MCPD ester reduction content (2.33 mg/kg), benzopyrene concentration content (0.95 μg/kg) and vitamin E consumption rate (67.86%) in F2 were lower than that in F1. Moreover, the oryzanol retention rate (87.84%) of F2 was higher than that of F1. In summary, F2 was more conducive to human health and more suitable than F1 in deep-frying. This information had an important directive on the industrial production of rice bran blend oil.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-022-05472-7.

Physicochemical stability and in-vitro bioaccessibility of concentrated γ-Oryzanol nanodispersions fabricated by solvent displacement method

Concentrated γ-Oryzanol nanodispersions were fabricated using milli-Q water (no emulsifier) or 0.1% (w/w) polysorbate 80 (T80), modified lecithin (ML) or sodium caseinate (SC) as emulsifiers. The freshly prepared nanodispersions had comparable particle diameter (118 to 157 nm), γ-Oryzanol concentration (1.75 to 1.92 mg mL^-1) and free-radical scavenging activity (59 to 62%) and had negative ζ-potentials (-22 to -59 mV), indicating that both γ-Oryzanol and emulsifier coexisted on the particles' interface. The nanoparticles had superior physicochemical stability up to 30 days of storage at 5 °C and were successfully autoclaved without excessive growth or aggregation. Nevertheless, they showed distinct physical stability upon storage at specific environmental conditions, which affected their In-vitro gastrointestinal digestion. Comprehensively, emulsifier-free nanodispersions were sensitive to acidic pH, NaCl and CaCl₂ addition. ML and SC coated nanoparticles were sensitive to Ca²⁺ ions, while T80 stabilized nanodispersions resisted to all environmental stresses, resulting in optimal simulated intestinal absorption.

Practical application of nanoencapsulated nutraceuticals in real food products; a systematic review

In recent decades, due to the increase in awareness, most consumers prefer foods that not only satisfy their primal urge of hunger but also include health-promoting effects on the body. Therefore, the food industry has an increasing tendency to apply the nutrients (like vitamins, essential fatty acids and minerals) and replace synthetic additives with natural bioactives (like phenolics and essential oils) to produce functional products. However, low dispersibility and shelf-stability as well as presenting unpleasant taste and odor are the most critical barriers for direct incorporation of these useful compounds into foods. In this context, nanoencapsulation has been proposed as a relatively new solution to overcome the mentioned limitations. However, fewer studies have focused on incorporating the bioactive-loaded nanocarriers into the food matrices. This study intends to help the development of functional food production by doing an exhaustive review on the incorporation of nanoencapsulated ingredients into the real food system and resulted interaction of nanocarriers and food products. According to the literature, incorporation of the nanoencapsulated bioactive ingredients into foods can be effectively used to enhance their stability during the processing and storage stage and their bioavailability as well as to delay lipid oxidation and microbial growth in food, without negatively affecting physicochemical, organoleptic and qualitative properties. However, some published results to date declared that food matrix might adversely affect the bioavailability and antimicrobial activity of nanoencapsulated ingredients. It seems that further studies are required to contribute to the choice of appropriate healthy ingredients and wall materials for incorporating into a given food structure.

Yogurt fortified with omega-3 using nanoemulsion containing flaxseed oil: Investigation of physicochemical properties

Flaxseed oil as a natural ingredient has many health benefits due to the rich contents of omega-3 fatty acids. However, its use in food formulations is limited because of low aqueous solubility, easy oxidation owing to the unsaturated nature of the fatty acids such as omega-3. The aim of this study was to prepare a stable nanoemulsion containing flaxseed oil and investigate the fortification of yogurt with this nanoemulsion compared with fortification with bulk flaxseed oil. The nanoemulsion of flaxseed oil-in-water was obtained by low-energy emulsification method. Optimized nanoemulsion contains 3% (w/w) flaxseed vegetable oil, 36% (w/w) surfactant, 10% (w/w) co-surfactant, and 51% (w/w) deionized water as a continuous phase. The result of transmission electron microscopy (TEM) showed that the optimal size was about 60 nm, which was stayed stable for 11 months. The results of gas chromatography (GC) indicated that the amount of omega-3 in nanoemulsion containing flaxseed oil was 27.3% and 19.8% after 7 days and 11 months, respectively. The turbidity results indicated the transparency of nanoemulsion after 11 months as well. The results of centrifuge experiments and thermal stress cycles exhibited that the optimized nanoemulsion was physically stable without any sign of creaming, phase separation, and cracking. In addition, pH and acidity of the yogurt fortified with nanoemulsion containing flaxseed oil were 4.22 and 1.41 wt%, respectively. In conclusion, fortifying yogurt with the nanoemulsion containing flaxseed oil can be considered as a solution to increase solubility, bioavailability, and protection of omega-3.

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.

Characterization of nanoemulsion of Nigella sativa oil and its application in ice cream

The aim of this study was to develop ice-cream product fortified with a Nigella sativa oil (NSO) nanoemulsion at four ratios (0% control, 3%, 5% and 10%). The NSO nanoemulsion stabilized by combinations of gum arabic, sodium caseinate, and Tween-20 at three ratios (5%, 10%, and 15%) of emulsifiers. The results showed that 10% nanoemulsion has the highest stability and zeta potential (-31.92), and lowest change of PDI (0.182). The 5% nanoemulsion showed the lowest particle size (175.83 µm). The result demonstrated that NSO nanoemulsion improved the ice-cream physical properties and consumer acceptability. Among the different samples, sensory evaluation revealed that ice-cream sample of 5% nanoemulsion received more acceptability from the panelist. This results demonstrated ice cream can be fortified with NSO nanoemulsion. This means it could be used as a functional ice cream with manifold NSO health benefits.

Formation of concentrated triglyceride nanoemulsions and nanogels: natural emulsifiers and high power ultrasound

The fabrication of concentrated nanoemulsions provides potential advantages such as loading capacity enhancement, storage and transportation costs reduction, and creation of novel textures. The current study investigated the capability of high power ultrasound on nanoemulsification of high concentration triglyceride using various natural emulsifiers (saponin, whey protein isolate, lecithin and sucrose monopalmitate). The impact of the emulsifier concentration (up to 6 wt%), oil content (up to 60 wt%) and exposure to sonication (up to 33 min) on the droplet size distribution, physical stability and rheological properties were evaluated. Regarding the dilute nanoemulsion (10 wt% oil), droplet size was inversely correlated with the concentration of emulsifiers, however only by using saponin (2 wt%) the droplet size was in nano range (d < 200 nm). The concentrated nanoemulsions (20–50 wt%) were also fabricated under sonication (15 min at saponin-to-oil ratio 2 : 10 w/w%). They also presented shear-thinning behavior with relatively low consistency coefficients. Surprisingly, the one with 60 wt% oil was easily converted to viscoelastic gel upon 3 min sonication. Owing to such characteristics, they could have potential applicability in formulation of soft foods, creams, sauces, salad dressings, pastes, lotions, cosmetics and pharmaceuticals.

The capability of ultrasonication and natural emulsifiers on nano-emulsification and nano-gelation of concentrated triglyceride oil was verified.

Improved Physicochemical Properties of Yogurt Fortified with Fish Oil/γ-Oryzanol by Nanoemulsion Technology

Fish oil has several dietary benefits, but its application in food formulations is limited because of its poor water-solubility, easy oxidation and strong odor. The purposes of this study were to produce a fish oil/γ-oryzanol nanoemulsion and to evaluate the effect of adding this nanoemulsion on the physicochemical and sensory characteristics of yogurts. Adding fish oil/γ-oryzanol nanoemulsion resulted in a significant reduction in the acidity and syneresis of yogurt. Yogurt with the nanoemulsion had significantly lower peroxide value (0.28 mmol/L after 21 days) and higher retention of eicosapentaenoic acid and docosahexaenoic acid contents (decreased to 95% and 94% of its initial value, respectively) than yogurt with fish oil/γ-oryzanol (peroxide value = 0.65 mmol/L; eicosapentaenoic acid and docosahexaenoic acid contents decreased to 72% and 53% of its initial value, respectively). Fish oil/γ-oryzanol nanoemulsion incorporated into yogurt had closer sensory attributes scores to plain yogurt. This study may have important implications for the application of fish oil/γ-oryzanol nanoemulsion in yogurt.

Releasing characteristics of anthocyanins extract in pectin-whey protein complex microcapsules coated with zein

This study investigated pectin-based capsules as delivery systems for purple rice bran anthocyanin extract (AE) during exposure to simulated gastrointestinal conditions. Four different capsules loaded with AE were prepared by ionotropic gelation/extrusion, including (1) pectin capsules (PE), (2) pectin capsules coated with zein (PE/ZE), (3) pectin-whey protein isolate complex capsules (PE + WP), and (4) pectin-whey protein isolate complex capsules coated with zein (PE + WP/ZE). CaCl2 in an ethanol solution with or without zein was used as a crosslinking solution. Swelling and release characteristics of all capsules under simulated gastric fluid at pH 1.2 (SGF) and simulated intestinal fluid at pH 6.8 (SIF) for 120 and 180 min, respectively, were examined. PE + WP, PE + WP/ZE, and PE/ZE capsules had higher encapsulation efficiency than PE capsules. After incubation, PE + WP/ZE and PE capsules had the lowest swelling ratio in SGF and SIF, respectively. PE + WP/ZE capsules had the lowest AE release in SGF, while PE capsules had the highest. Both PE + WP and PE + WP/ZE capsules had significantly lower AE release in SIF than PE and PE/ZE capsules. The study demonstrated that PE + WP and PE + WP/ZE capsules have potential to function as a slow release delivery system for AE.

γ-Oryzanol nanoemulsions produced by a low-energy emulsification method: an evaluation of process parameters and physicochemical stability

γ-Oryzanol is a natural antioxidant and nutraceutical compound, which makes it a good candidate for nutraceuticals, food supplements and pharmaceutical preparations.