The aim of this work was to study the influence of ι- and κ-carrageenan addition to strawberry sorbet prepared by various freezing methods (cryostat and conventional freezer) on freezing kinetics and ice crystals structure. Four variants of strawberry-based sorbet were prepared: with no additive, with 0.1% addition of ι- and κ-carrageenan, and 1:1 blend of both. Freezing curves and freezing time, as well as the size and morphology of ice crystals, were analyzed. The addition of carrageenan stabilizers resulted in freezing process elongation. Reference samples were characterized by different dynamics of the freezing process. The addition of carrageenan increased the final temperature of the samples, compared to the reference sample (even 2.6 °C of difference). Additives reduced ice crystals growth. The most efficient was mixture of both fractions of carrageenan--the samples in this variant frozen in conventional freezer were characterized by the smallest ice crystals diameter--average 5.44 µm, while for the reference sample it was 17.79 µm. PRACTICAL APPLICATION: This research can give a new path for the carrageenan's hydrolysates application--not only for dairy products. Iota carrageenan fraction was recommended for dairy products according to its water-holding capacity in the presence of calcium ions. This study showed that mix of ι- and κ-carrageenan could bring positive results to such product as sorbet without any milk proteins addition. This experiment data could also be helpful when optimizing frozen desserts production in small gastronomy--especially the temperature and time of freezing modifications.

中文翻译：

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添加ι-和κ-卡拉胶对不同方法冷冻草莓冰糕冷冻过程及冰晶结构的影响

这项工作的目的是研究在通过各种冷冻方法（低温恒温器和常规冷冻机）制备的草莓冰糕中添加 ι- 和 κ- 角叉菜胶对冷冻动力学和冰晶结构的影响。制备了四种草莓冰糕变体：不添加添加剂、添加 0.1% 的 ι- 和 κ-角叉菜胶，以及两者的 1:1 混合物。分析了冷冻曲线和冷冻时间，以及冰晶的大小和形态。角叉菜胶稳定剂的加入导致冷冻过程伸长。参考样品的特点是冷冻过程的不同动态。与参考样品相比，加入角叉菜胶提高了样品的最终温度（甚至相差 2.6 °C）。添加剂减少了冰晶的生长。最有效的是角叉菜胶的两种部分的混合物——在传统冰箱中冷冻的这种变体中的样品的特征是最小的冰晶直径——平均 5.44 µm，而对于参考样品，它是 17.79 µm。实际应用：这项研究可以为角叉菜胶的水解产物应用提供一条新途径——不仅限于乳制品。根据钙离子存在下的保水能力，建议将 Iota 卡拉胶部分用于乳制品。这项研究表明，ι- 和κ-角叉菜胶的混合可以为冰糕等产品带来积极的结果，而无需添加任何牛奶蛋白。在优化小型美食中的冷冻甜点生产时，此实验数据也很有帮助——尤其是冷冻修改的温度和时间。