•Green banana flour contains high amounts of resistant starch and phenolics.•Extrusion cooking of green banana flour changes physicochemical properties.•Properties of extruded green banana flour were ...influenced by feed moisture and screw speed.•Storing of extruded flours at 4°C increased the resistant starch content.
Green banana flour was extruded through a co-rotating twin-screw extruder with constant barrel temperature. The objectives of this study were to determine the effect of extrusion cooking variables (feed moisture, FM, 20% and 50%; screw speed, SS, 200 and 400rpm) and storing of the extruded flours at 4°C for 24h on the physicochemical properties, resistant starch (RS), pasting properties and antioxidant capacities. Extrusion cooking at higher FM and lower SS increased the amylose content, which was expressed in highest RS content. Water adsorption index (WAI) and pasting properties were increased, while water solubility index (WSI), total phenolic content (TPC) and antioxidant activities (FRAP, ABTS+, DPPH) in free and bound phenolics were decreased compared to the other extruded samples. Storing the extruded flours at 4°C for 24h prior to oven drying was the main factor leading to a further increase in the content of amylose, RS, TPC and WSI values, as well as pasting properties – in particular peak viscosity. Compared to native banana flour, extrusion cooking caused significant changes in all studied properties of the extruded flours, except for soluble DF and antioxidant capacity (ABTS+ and DPPH) of bound phenolics.
Green plantain flour (GPF) was used as a functional ingredient to produce gluten‐free (GF) bread based on a flour blend of rice flour and GF wheat starch (50:50) to improve their functional ...properties and to increase their resistant starch (RS) content. In pretrials, an addition of up to 30% GPF provided acceptable bread quality with maximum RS content. Based on these trials, two 2³ factorial screening experimental designs were applied, where water content, baking temperature and baking time of GF bread containing 30% GPF addition were optimised. The best baking conditions to achieve satisfying GF bread quality – higher loaf volume, softer crumb firmness and regular porosity structure at the highest RS content could be defined to a maximum addition of water at 160%, baking temperature of 180 °C and baking time of 90 min. The incorporation of GPF showed good potential to improve the quality of GF bread.
Nowadays, the nutritional value of cookies is relatively low. To reduce wheat flour usage in the cookies, the freeze-dried whole leaf (WL) and chloroplast-rich fraction (CRF) derived from Thai ...jasmine rice grass were used as a food ingredient to increase the nutrients of cookies. Chloroplast is a rich source of macro and micronutrients. Thus, the use of chloroplast might improve the nutrients in food products. This research aimed to study the physical and chemical characteristics of freeze-dried WL and CRF from Thai jasmine rice grass. The nutritional and physical properties of the butter cookies substituted wheat flour with WL or CRF (0%, 2%, and 4% (w/w)) were also investigated. The result showed that CRF derived from Thai jasmine rice grass contained a significantly larger amount of macro and micronutrients (protein, lipid, ash, -carotene, and total carotenoids) compared with WL (P≤0.05), except for carbohydrate, fiber, total chlorophyll, and total phenolic compound. Furthermore, the cookies replaced wheat flour with 4% WL from Thai jasmine rice grass, containing the highest fiber led to a decreased spread ratio and increased the hardness of cookies. Whilst the cookies substituted with 4% CRF (w/w) were similar in texture to the cookies containing only wheat flour (P>0.05). Moreover, the replacement of wheat flour with freeze-dried WL and CRF derived from Thai jasmine rice grass enhanced nutrients and antioxidant activity compared with cookies in the absence of WL and CRF. The butter cookies with 4% replacement of WL showed the highest level of chlorophyll and total phenolic; the cookies with 4% replacement of CRF contained the largest amount of -carotene (provitamin A) and total carotenoids. However, both cookies containing either WL or CRF were not significantly different in antioxidant activity (P>0.05).
Summary
Green plantain flour (GPF) is rich in indigestible carbohydrates, especially in resistant starch (RS). The objective of this study was to improve the functional pasta properties and RS ...content by producing gluten‐free (GF) pasta based on rice flour with different amounts of GPF addition (15–60% of total flour blend). Egg albumen (3.5–6.0% of total flour) and dough moisture (36–40%, dough humidity%), at constant emulsifier (0.5% of total flour) addition, were optimised in the first trials. The results showed that an addition up to 30% GPF with higher amount of egg albumen (6%) at dough moisture of 38% provided pasta with acceptable cooking quality and high RS content. Some qualities and/or RS content of GF pasta samples was further improved by adding 30% pregelatinised flours from the native GPF or drum‐dried green banana flour (DDGBF) in combination with applying varied steps of cooking and/or cooling, which were applied after pasta extrusion prior to drying them. The study suggests that GPF, in its native form, but particularly when pregelatinised, is a promising ingredient to be used for the production of GF pasta.
Green plantain flour has high resistant starch content. Gluten‐free pasta of acceptable quality was produced with an addition of 30% green plantain flour. Gelatinisation and retrogradation of the native green plantain flour changed their physicochemical properties and resistant starch content. Adapting the pasta processing method by introducing a cooling and cooking step after pasta extrusion prior to drying improved pasta cooking quality and resistant starch content.
