Orientadora: Profa. Dra. Paula Toshimi Matumoto Pintro

Data da Defesa: 23/02/2018



INTRODUCTION. Canistel (Pouteria campechiana (Kunth) Baehni) is a tropical fruit of the family Sapotaceae native from Mexico. It is grown in many countries from Central America, Africa and Asia. In Brazil it is cultivated by small farmers in the southeast. Fruits are oval shaped, have 1 to 4 seeds, thin and smooth peel, with creamy, dense flesh and intense yellow color. Has high nutritional value, is used medicinally in the preparation of teas, in the fight against fever, ulcers and applied in rashes. Medicinal benefits are related to its content of bioactive compounds such as carotenoids, polyphenols and flavonoids. Usually consumed fresh, beaten with milk or water, or as desserts (jams, jellies, sorbets and mousses). Ice cream industry is growing every year in Brazil. New ingredients are researched and added to ice creams with the aim of adding functionality and improving their technological features. Industry invests in technological innovations that contribute to the production process and the development/application of flavors that stand out in the market, which is highly competitive. Currently the use of exotic fruits has increased. Ice cream industries are looking for new flavors that preferentially enrich their products making them healthier and more attractive to increasingly demanding consumers.
AIMS. The objective of this study was to evaluate the effect of dehydration techniques on the phytochemical content of canistel pulp and to use the dehydrated pulp in the elaboration of ice cream, verifying the influence of its addition on the technological characteristics of the final product.
MATERIAL AND METHODS. Canistel (Pouteria campechiana (Kunth) Baehni) fruits were donated by the Experimental Station of Citriculture from Bebedouro (Sao Paulo, Brazil). Fruits were hygienized and dehydrated by freeze-drying (FD) and thermal dehydration (TD). Dehydrated pulp of both treatments (FD and TD) was submitted to analysis of bioactive compounds (total polyphenols, flavonoids and carotenoids), antioxidant activities (DPPH - 2,2-diphenyl-1-picrylhydrazyl, ABTS - 2,2’-azino-bis-3-ethyl benzothiazoline-6-sulfonic acid and FRAP - ferric reducing antioxidant power) and technological characteristics (color and hygroscopic properties). FTIR (Fourier Transform Infrared) and Raman spectroscopies were used to evaluate the FD, TD and FP (fresh pulp) pulps. Freeze-dryed pulp was chosen to be used in the preparation of ice cream formulations. Chemical composition of the pulp was determined. Three formulations were added 2 (IC2), 4 (IC4) and 6% (IC6) of canistel pulp and a standard formulation (IC0) without addition of pulp. Treatments IC0, IC2, IC4 and IC6 had their chemical composition analyzed and the technological characterization was performed by overrun tests, color stability (1, 7, 14, 21 and 28 days of storage), melting, rheological characteristics and sensorial analysis of IC2, IC4 and IC6 treatments.
RESULTS AND DISCUSSION. FD pulp showed more intense color, more quantity of total carotenoids. Heat treatment may have modified molecules of some flavonoids resulting in higher amounts of total polyphenols and flavonoids in the TD pulp. No differences in antioxidant activity were observed. C-C, C-C, C-O, C-O-C and H-O-H types of stretch vibrations were identified in both pulps by the FTIR spectrometric analysis. Raman spectroscopy showed characteristic vibrations of β-carotene. FD pulp presented higher water solubility (WSI), water absorption (WAI) and oil absorption capacity (OAC) than TD pulp. FD pulp presented 6.48% of proteins, 9.17% of lipids, 1.57% of ashes, 36.06% of carbohydrates and 1004.35 μg/g of β-carotene. Ice creams had no difference in their composition, except for the total carotenoid content, in which an increase was observed according to the addition of freeze-dried canistel pulp. Treatments also did not differentiate themselves regarding the incorporation of air (overrun). Color of the ice cream was affected by the addition of canistel pulp, making them more yellow according to the added pulp concentration. Color of both treatments remained stable in the storage period. Addition of canistel pulp to the ice cream formulation may have influenced the interaction of carotenoids with fat increasing the rate of melting. Rheological analyzes of the ice cream mix indicated that 6h of maturation is sufficient for gel formation to occur. Treatments IC2, IC4 and IC4 presented higher viscosity than the standard treatment (IC0). Sensory analysis the evaluated treatments the tasters did not identify difference in the attributes odor, texture and global appearance.
CONCLUSIONS. Dehydration techniques influenced the final quality of FD and TD pulps. FD pulp preserved a greater amount of carotenoids and flavonoids, impacting their color, hygroscopic properties and FTIR spectra. In the added ice creams of freeze-dried canistel pulp there was an increase in the amount of carotenoids. Ice cream color remained stable during storage. Carotenoid content in the added formulations of pulp influenced the melting speed due to the interactions between carotenoids and destabilized fat. Rheological tests showed that in 6h of maturation the ice cream mix gel was formed. IC6 showed higher viscosity. Both treatments obtained a positive evaluation in the sensorial analysis. Freeze-dried canistel pulp can be used as an alternative ingredient for the production of ice creams because of their physico-chemical characteristics and the appropriate technological features presented by the final product.
Keywords: dehydration, bioactive compounds, carotenoids, ice cream, rheology

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