Seyed Mohammad Hashem Hosseini

This study focused on fabricating linseed oil-in-water nanoemulsions (LON) at different pressures of 50 and 150 bar (named as LON50 and LON150, respectively) using a high-pressure homogenizer. Subsequently, these nanoemulsions were encapsulated in alginate hydrogel beads. It was observed that higher homogenizing pressure led to smaller droplet size (108.57 nm), harder beads (222.54 N), less LON release from the beads, and higher oxidation rate, as well as more reduction in α-linolenic acid content during the storage time. To increase the oxidative stability of LON₁₅₀, natural antioxidants including clove essential oil (CEO), rosemary extract (RE), and a mixture of both (CEO+RE) were separately incorporated into the oil phase of LON (LON_150-CEO), alginate aqueous dispersion (LON_150-RE), and both lipid and aqueous phases (named as LON_150-CEO+RE), respectively. It was shown that LON_150-CEO+RE had weaker mechanical properties than LON_150-RE and LON_150-CEO. In addition, this sample (LON_150-CEO+RE) showed the lowest oxidation rate and the minimum α-linolenic acid loss (9.82%) during storage. The highest LON release rate from the beads was related to LON_150-RE. The results of this study might help in designing bioactive lipids-filled hydrogel beads with appropriate chemical stability and mechanical properties.

Anthocyanins are valuable natural colorants but are inherently unstable when exposed to external factors. This study aimed to enhance the stability of sour cherry anthocyanins through copigmentation with tannic acid (TA) at a ratio of 1:0.25 (anthocyanin:TA), followed by encapsulation using maltodextrin (MD) or a combination of MD and Arabic gum (AG) in a 90:10 (w/w) ratio via spray drying. The resulting powders exhibited high encapsulation efficiency (97.27%–98.92%), low water activity, and excellent solubility (> 99.98%). Among the treatments, the copigmented anthocyanin powder encapsulated with the MD‐AG mixture showed significantly higher a* and chroma values, indicating a more intense red coloration. After 28 days of storage under three different conditions, the copigmented samples retained significantly more anthocyanin compared to noncopigmented samples. In model beverages, color stability remained consistent over 49 days of storage for both the encapsulated powders and the controls (anthocyanin extracts with or without TA). In conclusion, copigmentation with TA combined with encapsulation using MD‐AG wall materials presents an effective strategy for enhancing the stability and color retention of sour cherry anthocyanins.

In the present research, we aimed to create a novel controlled‐release device using two polymeric systems: beads of alginate hydrogel embedded with gellan fluid gel that contained Limosilactobacillus reuteri cells. Three different formulations, 1.5% alginate (Alg), 1.35%:0.15% alginate:gellan (Alg:Gel), and 1.2%:0.3% (Alg:Gel), were used in this research. We investigated the effect of this system on the physical properties of beads and probiotic viability, as well as application in sour cherry juice (for 8 weeks). The results showed that the presence of gellan fluid gel in the alginate microcapsules increased the hardness and diameter of the beads from 1.15 to 3.43 N and 1.71 to1.87 mm, respectively. Also, this system improved the viability of the microencapsulated bacteria under simulated gastrointestinal and thermal conditions (final counts of 7.17 and 7.00 logs CFU/mL, respectively). Regarding the probiotic viability during 28 days of storage (−18°C, 4°C, and 25°C), the counts of all treatments decreased during the storage, but the best results were observed at the freezing temperature (7.85 log CFU/mL). Raman confocal microscopy showed that the wall thickness of beads decreased by increasing gellan fluid gel from 10.3 to 8.6 μm. In the case of sour cherry juice, the viability of cells decreased in the range of 7.4–8.7 log CFU/mL, vitamin C in the range of 0.45–1.14 mg/L, and phenolic content in the range of 0.42–0.62 mg/L at the end of the storage period. As a result, the samples containing encapsulated L. reuteri, especially alginate/gellan fluid gel beads, showed better results. In summary, the beads made from 1.2% alginate and 0.3% gellan fluid gel proved to be an effective delivery and release system for L. reuteri cells and application in sour cherry juice.

Cow's milk is a nutritionally valuable food, although it lacks essential unsaturated fatty acids. Enriching milk with these fatty acids can reduce risks associated with cholesterol and saturated fats while meeting consumers' dietary needs. Grape seed oil (GSO), which is rich in omega-6 and omega-9 fatty acids, is one potential additive to replace milk fat and increase the unsaturated fat content. However, these essential unsaturated fatty acids are hydrophobic, making them difficult to dissolve in water, and are prone to oxidation, which can negatively affect the aroma and flavor of the milk. The layer-by-layer emulsion method is a promising approach to mitigate these challenges. This study investigated the enrichment of pasteurized skim milk with optimized multilayer emulsions of GSO and evaluated the physicochemical, microbial, and sensory characteristics of the milk over a storage period of 7 d at 4°C. Results indicated that single- and triple-layer emulsions remained stable within the milk matrix, but the 2-layer emulsion became unstable by d 3 of storage. During storage, acidity increased in all samples (from 0.16 to 0.44, 0.24 to 0.48, and 0.2 to 0.36 for single-, double-, and triple-layer emulsions, respectively), as did viscosity (from 1.53 to 1.9, 1.55 to 2.2, and 1.46 to 1.78 mPa·s, respectively), total microorganism count, peroxide value (from 5.52 to 17.6, 4.7 to 19.38, and 3.09 to 10.3 mEq/kg oil, respectively), and thiobarbituric acid index (from 0.43 to 0.52, 0.44 to 0.63, and 0.39 to 0.47 mg malondialdehyde/kg of oil, respectively). The pH values decreased slightly across all samples (from 6.6 to 6.5). No mold, yeast, or coliforms were detected in any sample throughout the study. Overall, the use of bioactive compounds such as essential fatty acids through milk enrichment can greatly enhance the quality of widely consumed dairy products.