Technological properties of precooked flour containing coffee powder and rice by thermoplastic extrusion

Abstract

Although Brazil is a country of tradition in both the production and consumption of coffee, the most of the coffee is consumed as a beverage, which reduces greatly the competitiveness on international market, for reducing the chances of supplying the product under other forms of consumption. Owing to that, the aim of this study was developing a precooked mixed flour containing coffee powder and rice for use in coffee flavored products. Mixtures of rice and coffee in the proportions of 900:100, 850:150 and 800:200 g, respectively, were processed in a single screw extruder (Brabender DS-20, Duisburg, German) and the effect of the extrusion process on the variables moisture content (16%, 18% and 20%) and temperature in the third extruding zone (140 °C, 160 °C and 180 °C) was studied. The results for expansion index ranged from 2.91 to 11.11 mm in diameter; the water absorption index from 4.59 to 6.33 g gel/g sample and the water solubility index varied from 4.05% to 8.57%. These results showed that, despite coffee powder influenced the variables studied, the expanded product after milling resulted in a extruded mixture with good absorption and water solubility indices, which favors the use of the precooked mixed flour for human consumption.

Micronised‐roasted coffee from unripe fruits improves bioactive compounds and fibre contents in rice extruded breakfast cereals

“…(2017) and Silva et al . (2013), who added commercial roasted coffee powder to sorghum flour and to rice flour, respectively. Besides the others process parameters, these different results may be associated with coffee micronisation by two factors.…”

“…Likewise, Silva et al . (2013) reported no changes in WAI with a substitution of up to 10% of rice flour for coffee powder at process temperatures of 160 and 180 °C. This behaviour may be due to the starch dextrinisation, which is known to reduce WAI, has not overcome the melting process.…”

“…Silva et al . (2013) showed the impacts of the concentration of coffee powder (7–23%), temperature (126‐194 °C) and moisture (15–21%) on the expansion, water solubility and absorption indexes of rice‐based extrudates, where the precooked flour was designated as an ingredient in food products. Chávez et al .…”

Characterization and nutritional value of precooked products of kiwicha grains (Amaranthus caudatus)

“…Did not show a significant difference between CPA (0.17 g/ml) and PK (0.18 g/ml) (p>0.05) in the BD, but there was significant difference with the raw grain (0.85 g/ml) and LK (0.38 g/ml) (p<0.05). The EI is of great importance in evaluating the product quality, since it is possible to verify whether the raw material used after the processing possesses suitable structure and composition for use as a food ingredient (Silva et al, 2013). The degree of expansion of an extruded product is closely related to the size, number, and distribution of air cells surrounded by the cooked material (Salata et al, 2014).…”

Adição de extrato de café crioconcentrado para aumentar compostos bioativos em cereal matinal à base de arroz

“…O café possui sabor característico de grande aceitação comercial e também propriedades estimulantes e funcionais. 1,3,4 . Nesse trabalho foi proposta a elaboração de um cereal matinal de farinha de arroz e extrato crioconcentrado de café (ECC) por extrusão termoplástica com o objetivo de avaliar os efeitos da adição de ECC sobre as propriedades tecnológicas e funcionais do produto.…”