Charakterystyka tekstury wybranych miksów tłuszczowych

Celem pracy było określenie wyróżników tekstury wybranych miksów tłuszczowych za pomocą testów penetracji z próbnikami stożkowym i cylindrycznym oraz w teście smarowności. Pomiary wykonano w kontrolowanych warunkach temperatury w 4 i 20°C. Miksy tłuszczowe zawierały od 62 do 70% tłuszczu ogółem, w tym tłuszcz mleczny stanowił w produkcie od 10 do 52%. Wśród badanych próbek najmniejszą twardością charakteryzowały się miksy, w których w fazie tłuszczowej przeważał tłuszcz mleczny w stosunku do dodanego tłuszczu roślinnego. Duża twardość miksów o zawartości tłuszczu roślinnego powyżej 45% mogła wynikać m.in. z zawartości nasyconych wyższych kwasów tłuszczowych w produkcie. Zastosowanie testu penetracji z wykorzystaniem końcówki stożkowej wpłynęło na większą powtarzalność pomiarów, co ułatwiło interpretację i ocenę tekstury badanych miksów w porównaniu do końcówki cylindrycznej. Smarowność miksów pogarszała się wraz ze wzrostem ich twardości.

Spreadable mixed fat product can be based on milk fat blended with vegetable oils or butter blended with vegetable fats. These fat blends are more popular because consumers expectthe products with attractive sensory properties of butter with spreadability typical for margarines. The texture of fat blends is one of most important feature in the quality evaluation. The aim of this study was an instrumental analysis of texture attributes of selected commercial fat blends with total fat content in the range of 62–70%. The content of milk fat in blends ranged from 10 to 52%. Texture of blends were analysed using the penetration tests with a cylinder probe P/5 and also with conical probe P/45C. Spreadability was measured using a TA-HDplus Texture Analyzer with a TTC Spreadability Rig. Thermal cabinet TCHD/LN2 integrated with a texture analyser provided an accurately controlled temperature environment during instrumental tests. The selected texture attributes (hardness, adhesiveness, consistency, stickiness, softness, spreadability) were analysed at temperature of 4 and 20°C. The results obtained at different temperature showed the decrease of hardness and penetration work was observed at room temperature. The lowest hardness was detected for blends with high content of milk fat. The samples with substantial addition of vegetables fats were harder what can be related with their composition e.g. the addition of palm oil can cause the increase of saturated fatty acids. The addition of vegetable oils caused the hardening of blends. The highest hardness and adhesiveness and the lowest spreadability values were recorded for blends with 10% of milk fat and 52% of vegetable oils (palm and linseed oils) as well as for blends of 25% of butter and 45% of vegetable fats. The higher hardness and the lower spreadability of fat blends was observed. It was concluded that the penetration test with a conical probe was well-suited and applicable for measuring the texture attributes of fat blend in comparison to penetration with cylindrical probe. The cone penetration test enabled to assay diversity of blends texture. The changes of penetration force of blends during the period when the samples were removed from refrigeration and brought to ambient temperature were also recorded. The hardness of sample 10/62 (contained 10% of milk fat and 52% of vegetable oils) significantly decreased during the first 20 min of exposure to room conditions. More stable in terms of hardness were blends with higher content of milk fat.