Qualidade da polpa de abacate em função da temperatura de congelamento e sua aplicação na produção de um pó liofilizado com leite de cabra.

Abstract

Freeze-drying is an effective technique for food preservation, ensuring the physicochemical and nutritional stability of the product. This study evaluated the influence of storage temperature of avocado pulp (-60°C and -80°C) and the freeze-drying process in formulations containing goat milk and maltodextrin. Three formulations were freeze-dried, varying the amount of pulp, milk, and maltodextrin. Physicochemical properties of goat milk, fresh and stored pulp were analyzed, along with the characterization of powdered formulations in terms of bulk and compacted density, solubility, hygroscopicity, and flowability. Goat milk showed fat, protein, and lactose contents within the legal standards, while the cryoscopic index was slightly lower than recommended. Regarding storage, results indicated that pulp stored at -80°C maintained better color preservation and structural stability, whereas pulp stored at -60°C retained more moisture, showed a reduction in total and reducing sugars, and had a significant increase in acidity. Among the powdered formulations, scanning electron microscopy analysis revealed no aggregation state among the particles. Additionally, the samples exhibited irregular geometric patterns and sharp edges. The second formulation, containing 15% maltodextrin, stood out with higher solubility, low moisture absorption, and good flowability. It was concluded that freeze-drying avocado pulp combined with goat milk and maltodextrin proved to be an efficient strategy for preservation and improvement of the product's physicochemical properties.