This study evaluated the effects of raspberry pomace addition on kefir’s chemical, microbiological, and sensory properties during a 14-day refrigerated storage. Kefir samples were prepared using 10% and 20% raspberry pomace, either retaining or straining out pomace after fermentation. Raspberry pomace notably enhanced antioxidant activity, peaking at 95.91% DPPH radical reduction on day 10, and increased total polyphenol content to 78.24 mg gallic acid/L. Pomace addition also improved microbiological stability, maintaining higher lactic acid bacteria (7.48 log CFU/mL) and stable yeast counts. Repeated measures ANOVA revealed a significant effect of storage duration on the concentrations of all analyzed parameters. Results showed that pomace-enriched samples, particularly those retaining pomace during storage, exhibited significantly higher levels of lactic, acetic, and citric acids, as well as ethanol and residual sugars. Sensory evaluations revealed kefir samples with strained raspberry pomace had the highest consumer acceptability, scoring 7.8 out of 9 for overall acceptance due to balanced flavor and improved texture. These results highlight raspberry pomace’s potential as a valuable ingredient for improvement in kefir, offering a promising approach to functional dairy innovation.

Natural biodegradable polymers such as chitosan are gaining increasing importance due to their favorable mechanical properties. Conversely, their limited antimicrobial and antioxidant activity requires enhancement with bioactive components. This study investigated the effect of Teucrium montanum L. hydrolate on the functional properties of chitosan films. The hydrolate was obtained as a by-product of hydrodistillation, and films were prepared with 0.6% (CH-TMh1), 0.8% (CH-TMh2), and 1.2% (CH-TMh3) hydrolate, along with a control film without hydrolate (CH). Hydrolate-enriched films exhibited greater thickness and elongation at break, with the highest values observed in CH-TMh3. The addition of hydrolate reduced moisture content (from 30.09% in CH to 12.25% in CH-TMh3), solubility, and swelling degree. Antioxidant activity increased significantly, with CH-TMh2 showing the highest free radical scavenging activity (92.9%) and total polyphenol content (38.78 mg GAE/g). Films containing hydrolate also displayed pronounced antimicrobial activity, with the largest inhibition zones against S. aureus ATCC 25923 (16.33 mm). Moderate activity was observed against B. subtilis, while there was no activity against C. albicans ATCC 2091. These results confirm that chitosan films enriched with T. montanum L. hydrolate possess improved mechanical, antioxidant, and antimicrobial properties, making them promising for potential application in the packaging of specific food products.