Elaboração de recheios à base de polpas de frutas para injeção em biscoitos de cereais integrais obtidos por coextrusão

Abstract

Despite the current preoccupation with an increasingly natural food, it is known that industrialized or highly processed foods are increasingly present in food habits of the population. Within this group of foods, stuffed sweet biscuits are highlighted, being characterized by high calorie that is due to high levels of fats and sugars present in their formulations. The process of thermoplastic extrusion is widespread in the category of crackers, especially those based on corn, but this technology can also be applied in the development of sweet biscuits stuffed. Whole cereal cracker formulations provide improvements in the nutritional properties, by increasing the content of dietary fiber, particularly insoluble. To maintain nutritional benefit, it is necessary to incorporate a sweet fillings which also adds functional benefits to the final product. The fruits are good choices for this type of product, its sensory benefits, in addition to high levels of soluble fiber and antioxidants. Thus, the aim of this study was to develop formulations for biscuit fillings processed by coextrusion, differentiated in relation to that currently exist in the market which have high levels of saturated vegetable fat. The biscuits were developed with whole grain flours such as corn, rice and sorghum, in equivalent proportions and the fillings were made with different fruit pulps (guava, açaí and pineapple), sucrose, glucose powder, high pectin and low methoxyl ( ATM and BTM), polyols, maltodextrin, citric acid as an acidulant, sodium citrate as a stabilizer and sodium benzoate as a preservative. One of the important parameters in the preparation of the formulations was the low water activity of the fillings, which was in the range of 0.6, lower than desirable (0.5). The físcio-chemical characterization of fillings showed that the pH of the formulations was close to 4.5, especially the filling of Açai and also showed a high content of total solids due to the high concentration in the processing. With respect to rheological evaluation, the fillings made of the three types of pulp presented pseudoplastic behavior, and the model of Herschel-Bulkley was the best in describing the flow. In addition, the guava was more structured and less physically suffered the effects of temperature rise. The evaluation of the stability of the already filled biscuits, during storage, by instrumental texture tests demonstrated that the balance between the two dies (and biscuit filling) has been reached between the eighth day and the fifteenth day of storage. Comparison of the chemical composition of cookies developed with similar existing in the market showed that there was a reduction of lipid content and calorie and increased soluble fiber content, especially for the biscuit guava stuffed.