TAMARILLO PULP FLOURS: NOVEL HIGH PROTEIN FOOD INGREDIENTS PRODUCED BY DIFFERENT DRYING METHODS

The whole fruit pulp of tamarillo (Solanum betaceum Cav.) has been widely consumed due to its rich composition in nutrients such as sugars, proteins, fibers, and minerals. Several products based on tamarillo have been developed, such as juices, jellies, and yogurts. Furthermore, it has been used as coagulant, antioxidant against lipid oxidation, emulsifier, and foam stabilizer in food products. This fruit is native mainly to South America (Andean regions of Colombia, Peru, Chile, Ecuador, and Bolivia) and presents increasing cultivation and use as a non-conventional food plant (PANC) in Brazil. In addition, there is a growing demand for new ingredients with functional appeals that can replace conventional ingredients to enrich nutritionally and provide new gastronomic experiences. This study aimed to produce flour from tamarillo pulp by different drying methods and quantify the crude protein content so they could be used as potential functional ingredients. The tamarillo fruits were purchased from the Companhia de Entrepostos e Armazéns Gerais de São Paulo, blanched to remove the outer peel, which imparts a bitter taste, and centrifuged to obtain the whole pulp. The pulp was dehydrated using the following methods: in a MARCONI® model MA 035 oven with air circulation and renewal at a temperature of 55 ̊C ̸26h; in a TERRONI® model LD3000 lyophilizer at a temperature of - 37 ̊C ̸48h; by foam mat dryer (5% albumin/100g of pulp). For foam formation, a Britania® brand mixer with an 8-stem beater was used at a speed of 500 w ̸ 10 min. Then, the foam was spread on trays of the COLZER® dehydrator model ST-04(T) 500 w with air circulation and renewal at 70ºC ̸ 1 h and 50 min. The crude protein content was quantified using AOAC (2010) method n. 2001.11, where the total nitrogen content was determined by the Kjeldahl method (N= 6.25). Acid digestion was performed with sulfuric acid under heating at 350 °C and distillation with boric acid. The fraction obtained was titrated with a standardized 0.02 N HCl solution. The analyses were performed in quadruplicate. The protein values were 9.89% for oven-dried pulp flour, 9.49% for freeze-dried pulp flour, and 29.91% for pulp flour by the foam mat dryer process in a dehydrator. According to RDC 54 (2012), which determines the minimum content of 6 g of the nutrient for each portion of 100 grams of the product, we can classify the tamarillo pulp flour obtained by the foam mat dryer process in the dehydrator as a high protein content ingredient, while the oven-dried and freeze-dried pulp flours are classified as protein source ingredients. Therefore, the tamarillo pulp flours obtained by different drying methods can be considered as a potential ingredient that can be used to increase the protein content in new formulations to encourage and enhance the consumption of this PANC.