Buttermilk, the by‐product of butter production, due to good technological features and excellent nutritional and health‐promoting properties finds more and more applications in food industry. Considerable amount of polar lipids causes that buttermilk exhibits emulsifying and stabilizing effect and may be used to improve the product quality. The study aimed to design new kind of ice cream, in which all milk is substituted by buttermilk. Within the study, we compared physicochemical parameters, color, texture, and sensory properties of control milk ice cream (C), ice cream from sweet buttermilk (SB), and ice cream from cultured buttermilk (CB). Ice cream was tested on the production day, and some characteristics were tested also after 14 and 28 days of storage at −18 ± 1°C. The study showed that samples of ice cream from cultured buttermilk had the highest acidity and were the most resistant to melting. The samples did not differ in over‐run value. The use of buttermilk influenced the texture of ice cream and product from sweet buttermilk had the highest stickiness during the storage. The color analysis showed that the highest lightness parameter had ice cream from cultured buttermilk, while samples from sweet buttermilk had the most greenish‐yellow characteristics. All the obtained products had good sensory characteristics, only cultured buttermilk ice cream slightly deteriorated after 28 storage days. Good quality properties cause that buttermilk may be successfully used as substitution of milk in ice‐cream formula and may improve its quality by exhibiting of some emulsifying stabilizing effect.

The food industry is looking for natural additives to improve acid curd cheese (tvarog), while shrimp by-products are being wasted. The concentrated astaxanthin lipid preparation (ALP) was recovered from shrimp shells and added (0%, 0.25%, 0.5% and 1%) to tvarogs stored up to 4 weeks at 5 ± 1 °C. The addition of ALP increased the lipid content and decreased the moisture in cheese. Water activity, acidity and hardness of tvarogs differed significantly between cheese variants. The cheeses with ALP had more stable and lower pH after 4 weeks of storage, and higher titratable acidity immediately after ALP addition. The 0–0.5% ALP samples had the same level and changes in lipid oxidation, while the 1% ALP cheese had more stable thiobarbituric acid values during storage. This may be due to several times greater antioxidant activity (DPPH assay) in the cheese with the highest ALP addition. The addition of astaxanthin had create popular salmon colour and improved objective colour parameters of the cheeses. The best sensory features had 0.5% ALP sample. A higher addition of astaxanthin preparation caused a foreign aftertaste. The use of astaxanthin from shrimp shells to acid curd cheeses enables the creation of new functional properties that are increasingly popular with consumers.

The dairy industry releases huge amounts of by-products. One of them is buttermilk, obtained during butter production. This by-product is characterized by high nutritional and technological value and is finding more and more applications in food production. This study aimed to produce and analyze the characteristics of quark cheese obtained entirely from buttermilk during 3-week refrigerated (4 ± 1 °C) storage. Four kinds of sour buttermilk were used: two from industrial butter production, and another two from butter production at laboratory scale. Laboratory buttermilk differs in the kind of starter culture used in the production. The evaluation of cheese quality properties included physicochemical analyses, texture measurement, and sensory assessment. The results showed that the kind of buttermilk used in production influences the acidity, total solids, textural characteristics, and fat content of the obtained quark cheeses. All obtained cheeses had very high sensory quality throughout the storage period. The study indicates that buttermilk may be successfully used as a substitution for milk in quark cheese production.