Influence of Microencapsulation on Organoleptic Quality of Probiotic-Fortified Oat Milk

Introduction

The demand for non-dairy functional beverages has increased due to the growing trend toward plant-based diets. Oat milk's mild flavour, balanced nutritional makeup, and consumer-friendly sensory profile have made it a promising substitute for traditional dairy milk. It is naturally high in vitamins, dietary fiberfibre, β-glucan, and bioactive substances that support good health. Oat milk makes an excellent carrier matrix for functional ingredients like probiotics because of its neutral flavour and creamy texture. Probiotics are live microorganisms that confer health benefits when consumed in adequate amounts [3] . However, their incorporation into beverage systems presents technological challenges, including reduced viability and potential effects on sensory quality. Microencapsulation has been explored as an effective strategy to enhance probiotic survival and stability by forming protective matrices around probiotic cells [10] . The present study aimed to evaluate the sensory characteristics of oat milk incorporated with different levels of microencapsulated probiotics and to identify the most acceptable formulation based on organoleptic evaluation.

Materials and Methods

Raw Materials

Rolled oats were procured from a local retail market. Distilled water was used for beverage preparation. Probiotic cultures were maintained under appropriate laboratory conditions prior to encapsulation. All chemicals and reagents used were of analytical grade.

Preparation of Oat Milk

Oat milk was prepared using an enzymatic hydrolysis method. One kilogram of rolled oats was ground into fine flour and mixed with 2.70 kg of water to form an oat slurry. The slurry was treated with α-amylase (77.78 mg per kg of rolled oats) to facilitate starch hydrolysis. The mixture was filtered to separate the liquid fraction from the filter cake. The filtrate obtained was collected as oat milk (2.85 kg) and used for further fortification [11] .

Oat Slurry Formation ↓ Enzymatic Hydrolysis (α-Amylase 77.78 mg/kg) ↓

Filtration ↓

Addition of Probiotic Microcapsules

Fig 1:

Illustrates the stepwise process involved in oat milk preparation, including mixing, enzymatic hydrolysis, filtration, and subsequent incorporation of probiotic microcapsules

Preparation of Microencapsulated Probiotics

Microencapsulation of probiotic cultures was carried out using a hydrocolloid-based encapsulating system. The probiotic culture was dispersed within the encapsulating matrix under aseptic conditions to obtain stable microcapsules. Different formulation combinations were prepared to obtain twenty treatments (T1-T20) [10] .

Incorporation into Oat Milk

The prepared microcapsules were incorporated into freshly prepared oat milk under continuous stirring to ensure uniform distribution. Each formulation was prepared separately and stored under refrigerated conditions until sensory evaluation.

Sensory Evaluation

Sensory evaluation was conducted using a semi-trained panel. Samples were coded and presented in randomised order. Colour, taste, texture, flavour, appearance, and overall acceptability were evaluated using a nine-point hedonic scale (1 = dislike extremely; 9 = like extremely).

Statistical Analysis

All experiments were performed in triplicate, and results were expressed as mean±standard deviation. Data were analysed using analysis of variance (ANOVA) to determine significant differences among treatments at p ≤ 0.05 [7] .

Results and Discussion

Sensory Evaluation of Microencapsulated Probiotic Oat Milk

Sensory characteristics play a crucial role in determining the consumer acceptability of functional beverages. In the present investigation, oat milk incorporated with different levels of microencapsulated probiotic formulations (T1-T20) was evaluated for colour, taste, texture, flavour, appearance, and overall acceptability using a nine-point hedonic scale.

The results are presented in Table 2.

A significant (p ≤ 0.05) difference was observed among treatments for all sensory attributes, indicating that variation in microcapsule composition influenced organoleptic quality [5] .

Colour

Colour scores ranged from 5.9 to 8.5. The highest colour score was recorded for T18 (8.5±0.08) followed closely by T13 (8.1±0.08), both belonging to statistical group "a". The improved colour in these treatments may be attributed to optimal microcapsule dispersion and minimal opacity changes in the oat milk matrix. In contrast, the lowest colour score was observed in T7 (5.9±0.06), possibly due to higher encapsulant concentration affecting visual clarity [12] .

Taste

Taste is one of the most critical parameters influencing product acceptance. The taste scores ranged from 5.3 to 8.2. Treatment T18 (8.2±0.08) and T13 (7.9±0.08) showed significantly higher taste scores (p ≤ 0.05), indicating better flavor balance and absence of undesirable aftertaste. Lower taste scores in treatments such as T7 (5.3±0.06) may be associated with excessive hydrocolloid concentration leading to slight bitterness or altered mouthfeel [2] .

Texture

Texture scores varied between 5.8 and 8.5. The highest texture acceptability was again observed for T18 (8.5±0.08) and T13 (8.1±0.08). The improved texture in these treatments suggests proper microcapsule integration without phase separation or sedimentation. Excessive encapsulating material in some treatments might have caused slight grittiness, reflected in lower scores for T7 [4] .

Flavour

Flavour scores ranged from 5.1 to 8.1. Treatment T18 (8.1±0.08) achieved the highest score, followed by T13 (7.8±0.08). The enhanced flavour profile may be due to effective encapsulation protecting probiotic viability while preventing off-flavour development. Treatments with lower scores possibly experienced minor flavour masking or textural interference [8] .

Appearance

Appearance scores ranged from 5.9 to 8.8, with T18 recording the highest value (8.8±0.08). The smooth dispersion and stable suspension of microcapsules likely contributed to superior visual appeal. Treatments showing moderate sedimentation tendencies exhibited comparatively lower appearance scores [6] .

Overall Acceptability

The total perception of all sensory characteristics is known as overall acceptability. Scores varied significantly (p ≤ 0.05) among treatments, ranging from 5.9 to 8.4. T13 showed the highest overall acceptability (8.4±0.08). T18 (8.0 +/-0.08).

These treatments showed better sensory performance because they were in statistical group "a." The outcomes unequivocally show that optimal microencapsulation levels improve consumer acceptability without compromising organoleptic quality. On the other hand, T7 showed the lowest overall acceptability (5.9±0.06), indicating that beverage palatability may be negatively impacted by an excessive amount of encapsulating matrix.

The results indicate that the successful production of a highly palatable functional oat milk beverage can be achieved through appropriately optimized microencapsulated probiotic incorporation [1] . Mean sensory scores for colour, taste, texture, flavour and appearance across treatments (T1-T20).

Conclusion

The current study showed that when formulation parameters are properly tuned, it is possible to incorporate microencapsulated probiotics into oat milk without sacrificing sensory quality. All assessed sensory qualities showed significant changes between treatments, indicating that the level and makeup of encapsulating materials are important factors in affecting the acceptability of a product. Colour, taste, texture, flavour, appearance, and general acceptance were the areas where T13 and T18 performed the best out of all the developed formulations. These treatments' enhanced organoleptic qualities imply that optimal microencapsulation enhances beverage stability and mouthfeel in addition to protecting probiotic organisms. Conversely, formulations containing relatively higher encapsulating matrix levels showed reduced sensory preference, indicating the importance of balanced formulation design. In general, the results show theAll that all assessed sensory qualities showed significant changes between treatments, indicating that the level and makeup of encapsulating materials are important factors in affecting the acceptability of a product. Color, taste, texture, flavour, appearance, and general acceptance were the areas where T13 and T18 performed the best out of all the developed formulations. These treatments' enhanced organoleptic qualities imply that optimal microencapsulation enhances beverage stability and mouthfeel in addition to protecting probiotic organisms.

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