Optimization of pumpkin and feed moisture content to produce healthy pumpkin-germinated brown rice extruded snacks

Impact of moisture content on microstructural, thermal, and techno-functional characteristics of extruded whole-grain-based breakfast cereal enriched with Indian horse chestnut flour

The use of non-conventional seed flour is of interest in obtaining healthy breakfast cereals. The research aimed to study the physico-functional, bioactive, microstructure, and thermal characteristics of breakfast cereals using scanning electron microscopy, X-ray diffractometry, and differential scanning calorimeter. The increase in feed moisture content (16 %) enhanced the bulk density (5.24 g/mL), water absorption index (7.76 g/g), total phenolic content (9.03 mg GAE/g), and antioxidant activity (30.36 %) having desirable expansion rate (2.84 mm), water solubility index (48 %), and color attributes. The microstructure showed dense inner structures with closed air cells in extruded flours. Extrusion treatment rearranged the crystalline structure from A-type to V-type by disrupting the granular structure of starch, reducing its crystallinity, and promoting the formation of an amylose-lipid complex network. Increasing conditioning moisture enhanced the degree of gelatinization (%), peak gelatinization temperature (Tp), and starch crystallinity (%) and reduced the gelatinization enthalpy (ΔHG) and gelatinization temperature ranges. The results reported in this study will help industries to develop innovative and novel food products containing functional ingredients.

Optimization of the iron-enriched extruded snack containing jackfruit seed flour, mung bean flour and ferrous ammonium phosphate by using response surface methodology

The Food and Agriculture Organization (State of food and agriculture. Moving forward on food loss and waste reduction, 2019) stated that approximately 1.3 billion tons of food wasted every year caused the emission of around 4.4 gigatons of greenhouse gas. World Health Organization highlights that iron deficiency affects billions of people worldwide and remains the leading cause of anemia. With the growth of healthy and sustainable diets and consumers’ better understanding of the relationship between diet, health, and the environment, there is an opportunity to develop novel healthy extruded snacks. The present study was carried out using response surface methodology to investigate the effects of varying proportions of jackfruit seed flour, mung bean flour, and ferrous ammonium phosphate on physical and functional properties of extruded snacks. Experiments were carried out using a central composite rotatable design with three independent parameters such as jackfruit seed flour(%), mung bean flour(%), and ferrous ammonium phosphate (%), and five responses such as bulk density (BD), expansion ratio (ER), hardness, color difference (ΔE), and iron content. It was found that ferrous ammonium phosphate significantly increased the iron content. Bulk density, expansion ratio, and hardness were significantly affected by jackfruit seed flour and mung bean flour. All independent variables significantly influenced colour value. The optimized iron-enrich extruded snacks were obtained at 24.87% jackfruit seed flour, 20.95% mung bean flour, and 0.021% ferrous ammonium phosphate. The optimized extruded snack contained 15.32 g/100 g protein and 22.03 mg/100 g iron content. Results of the study indicate that the optimized extruded snack could be used as a protein and iron source to mitigate malnutrition and anemia.

Graphical Abstract

Effects of particle size and moisture content of maize grits on physical properties of expanded snacks

The main aim of this research was to investigate the effects of simultaneous changing of maize grits particle size and moisture content on some physical properties and microstructure of the expanded snacks produced by an industrial single screw extruder. Maize grits with different particle sizes of 212-299, 300-474, 475-680, 681-870, 871-1,016, and 1,017-1,070 μm and various moisture contents of 15, 16, 17, and 18% were used to manufacture puffed products. The samples produced with larger particle sizes and higher moisture content exhibited lower water absorption and water solubility indices and less expansion and crispiness than other samples. As microstructure results revealed, these samples showed more uneven surface and thicker cross-section. Overall, controlling both moisture content and particle size of maize grits had significant effects on the quality of the snacks. However, the impact of changing particle size on the snack properties was greater than changing the moisture content. This research has implications in food industry in production of puffed snacks using extrusion process. The results provide practical and green methods of improving the quality of the snacks by choosing the appropriate feed particle size and moisture content. The approach introduced in this paper is easy to impediment in the food industry without the need to change extruder configuration or adding to the list of ingredients and additives.