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The present research was envisaged with an aim to optimize the system and the product responses for the development of tomato pomace-incorporated corn-based extrudates employing central composite rotatable design and determine its proximate, lycopene, consumer acceptability and storage studies.

Lycopene-rich extrudates were developed from corn flour blended with different levels of tomato pomace. The independent extrusion variables, namely, feed composition (95:5 to 75:25), feed moisture (12–20%), screw speed (200–600 rpm) and barrel temperature (125–185 °C), were studied to determine their influence on dependent variables, namely, specific mechanical energy, hardness, water solubility index, lateral expansion, water absorption index, bulk density and color.

All of the quality parameters were significantly (p < 0.05) influenced by independent variables. The regression models obtained for all the responses showed high coefficients of determination (R2 = 0.85–0.95). The optimum conditions for the development of tomato pomace-incorporated corn-based extrudates were feed composition (90:10), feed moisture (14%), screw speed (300 rpm) and barrel temperature (170 °C). The moisture, fat and carbohydrate contents of the extrudates were significantly reduced, whereas protein, ash and fiber were significantly (p < 0.05) enhanced after the incorporation of tomato pomace. Aluminum laminates were found to be the suitable packaging materials for extrudates for a period of 120 days in comparison to high-density polyethylene packages.

As far as the authors could possibly know, scanty literature exists wherein the tomato pomace has been utilized for the development of lycopene-rich corn-based extruded snacks. Such extrudates with significantly higher fiber and lycopene contents than corn flour will serve as a suitable alternative for the development of shelf-stable ready-to-eat extruded snacks.

The purpose of this paper is to investigate the effect of residence time distribution in extruders along with the incorporation of nutraceuticals on the final quality of the products with respect to several pivotal responses.

Corn–rice flour blend fortified with isolated nutraceutical concentrates at two (low and high) levels was extruded at barrel temperature (110°C), screw speed (260 rpm) and feed moisture (17 percent). Extrudates were collected at an interval of 24 s followed by analysis for radial expansion (RE), bulk density (BD), water absorption index (WAI), sensory score (SS), textural hardness, colorimetric values (L*, a* and b*) and color difference (E).

The entire data were fitted to zero- and first-order kinetic models. There was a gradual decrease in RE, SS and L* value, whereas an increase in BD, textural hardness and a* value of extrudates fortified with the three nutraceutical concentrates was observed with the successive time interval of 24 s along with a more pronounced effect on color difference (E) observed during the last stages of extrusion time. The zero-order kinetic model was well fitted for BD and a* value, whereas the first-order kinetic model showed better results for RE, WAI, SS, textural hardness, L* value, a* value and b* value of fortified extrudates.

Nutraceuticals like β-glucans, lignans and γ oryzanol exhibit numerous health-beneficial effects. This study analyzes the kinetics of changes in various responses of extrudates fortified with these nutraceutical concentrates during extrusion.

This paper aims to understand the effect of extrusion conditions on the degree of foaming of polylactic acid (PLA) during three-dimensional (3D) printing. It was also targeted to optimize the slicing parameters for 3D printing and to study how the properties of printed parts are influenced by the extrusion conditions.

This study used a commercially available PLA filament that undergoes chemical foaming. An extrusion 3D printer was used to produce individual extrudates and print samples that were characterized using an optical microscope, scanning electron microscope and custom in-house apparatuses.

The degree of foaming of the extrudates was found to strongly depend on the extrusion temperature and the material feed speed. Higher temperatures significantly increased the number of nucleation sites for the blowing agent as well as the growth rate of micropores. Also, as the material feed speed increased, the micropores were allowed to grow bigger which resulted in higher degrees of foaming. It was also found that, as the degree of foaming increased, the porous parts printed with optimized slicing parameters were lightweight and thermally less conductive.

This study fills the gap in literature where it examines the foaming behavior of individual extrudates as they are extruded. By doing so, this work distinguishes the effect of extrusion conditions from the effect of slicing parameters on the foaming behavior which enhances the understanding of extrusion of chemically foamed PLA.

This study aims to develop sweet chestnut incorporated corn-based extrudates by the optimization of process conditions.

The independent process variables for extrusion (blend ratio, barrel temperature, screw speed and feed moisture) were investigated to govern their impact on reliant variables, namely, bulk density, specific mechanical energy, water absorption index, water solubility index, color and hardness. Product and system responses were significantly (p < 0.05) affected by the independent variables. Experimental design with quadratic models experienced a high coefficient of determination (R² = 0.99).

Numerical optimization for the development of extrudates resulted in optimum conditions having corn flour: sweet chestnut flour (80:20), barrel temperature (120°C), screw speed (340 rpm) and feed moisture (12%). Fat, moisture and protein contents of the developed extrudates using optimum conditions were significantly (p < 0.05) lower compared to raw materials – corn and sweet chestnut. The packaging of extrudates in aluminum laminates revealed shelf stability of three months at room temperature without deterioration of quality.

Nutritionally rich sweet chestnut extruded products would be an exclusive option to already existing snacks in the market and can facilitate a new sphere in extruded product sector.

This study aimed to evaluate the enrichment with UD powder effects on phenols, antioxidant capacity, color, texture and extrusion parameters of extruded snacks.

Extrudates were produced with a single-screw extruder. It operated at a 3:1 compression ratio, loaded with prepared corn samples at a constant dosing speed of 18 rpm. The screw was rotated constantly at 150 rpm and temperatures of barrel sections 1–4 were set to 25, 70, 170 and 175°C, respectively; the nozzle diameter was 3 mm.

Extrudate parameters were fitted against UD concentration and presented equations close to the experimental data, according to the obtained adjusted R². Using UD powder in the mixture to obtain extruded corn snacks increased their phenols content and antioxidant capacity. However, high UD concentration in the mixtures caused low expansion and porous extrudates; nevertheless, it lowered possible molecular damage risk by molecules solubilized in water, making them more stable. Using 7.5% UD percentage in mixtures is recommended for extruded snacks to maintain typical extrudate characteristics. Higher UD concentration provokes more hygroscopic, dense and compact snacks.

These findings confirm that using U. dioica L. powder in the mixture to obtain extruded corn improves the functional value of snacks, maintaining extruded characteristics.

This paper aims to target to print functionally gradient materials (FGM) devices made of immiscible polymers in multi-material fused deposition modelling (FDM) systems. The design is intended to improve adhesion of dissimilar thermoplastics without the need for chemical compatibilization so that filaments from many different sources can be used effectively. Therefore, there is a need to invent an alternative solution for printing multiple immiscible polymers in an FDM system with the desired adhesion.

In this study, the authors have developed a bi-extruder for FDM systems which can print two thermoplastics through a single nozzle with a static intermixer to enhance bonding between input materials. The system can also change the composition of extrudates continuously.

The uniqueness of this extruder is in its easy access to the internal channel so that a static intermixer can be inserted, enabling deposition of mechanically interlocked extrudates composed of two immiscible polymers. Without this intermixer, the bi-extruder extrudes with simple side-by-side co-extrusion having no mechanical interlocking. The bi-extruder was characterized by printing objects using pairs of materials including polylactic acid, acrylonitrile butadiene styrene and high impact polystyrene. Microscope images of the cross-sections of the extrudates confirm the ability of this bi-extruder to control the composition as desired. It was also found that the mechanically interlocked extrudates composed of two immiscible polymers substantially reduces adhesion failures within and between filaments.

In this study, the first-ever FDM extruder with a mechanical blending feature next to the nozzle has been designed and used to successfully print FGM objects with improved mechanical properties.

The utilisation of food waste/by‐products helps to increase produce recovery and enhances nutrition in low‐cost food without any appreciable increase in product cost. The storage behaviour of the product must be studied before commercialisation of the product. This paper aims to focus on this process.

Extrudates (25 g) prepared under optimised conditions of proportion (rice flour, pulse powder and carrot pomace), moisture content, screw speed and die temperature, were sealed using a polythene sealing machine in LDPE bags and aluminium laminated LDPE bags. The bags were then stored for six months in an incubator at temperature of 38±2°C to evaluate the stability of the product. The extrudates were analysed for change in colour, hardness, moisture content and sensory characteristics.

Zero‐ and first‐order models were fitted for prediction purposes. The minimum overall change in color ΔE value, minimum increase in moisture content and minimum increase in hardness was observed in aluminium laminated LDPE bags. The zero order model better predicted the variation of L*, b*, ΔE, moisture content and hardness during storage, whereas first order model was better fitted for the a* value.

The carrot pomace has the potential to be used as a food ingredient that enhances the nutritional attributes of products along with a reduction in cost. Extruded products were successfully developed in the laboratory using carrot pomace as one of the ingredients. This study evaluates the kinetic changes during the storage of carrot pomace based extruded snacks.

Fura is a traditional thick dough ball snack produced principally from millet or sorghum which is common in Nigeria. It is consumed with nono (local fermented milk) or mashed in water before consumption in the form of porridge. The purpose of this paper is to study the optimization of feed composition, feed moisture and screw speed on acceptability and hydration properties of fura extrudates from pearl millet and soybean flour mixtures.

The effects of extrusion conditions feed composition (ratio of soybean to millet), percentage moisture wet basis and screw speed (rpm) on the hydration properties and the acceptability of fura from millet‐soybean flour mixtures were studied using a single screw extruder. Response surface methodology (RSM) was adopted to evaluate the hydration properties responses of fura extrudates.

The models showed R²=0.863, 0.825, 0.898 and 0.741 for hydration power (HP), effect of quantity of water on swell volume (EQWSV), wettability (WTBLTY) and viscosity respectively indicating that the model was a good fit and could be used to navigate the design space. The result indicates that increasing the level of soybean flour resulted in decreased HP of fura extrudates. The overall acceptability sensory scores show that the fura extrudate design point 11 representing 20 percent soybean, 16.6 percent feed moisture and 200rpm recorded the highest acceptability (7.25) with significant differences from the other extrudates in terms of colour, flavor, texture and overall acceptability.

The extrusion cooking data from this study could help predict the expected performance in investigations of potential use of millet and soybean to explore the possibility of industrial projection.

Snack industry is one of the fastest growing food sectors globally, and people are nowadays conscious about intake of healthy snacks on regular basis. There is enormous variety of ready-to-snacks available in the market. Brown rice though highly nutritious in comparison to polished rice is consumed meagerly by masses. Each raw material/ingredient used in extrusion cooking requires specific control of processing variables to meet acceptable product characteristics and consumer demands, which in turn necessitates the need to optimize the conditions for development of brown-rice-based snacks. The aim of this study was to optimize the extrusion cooking conditions for development of brown-rice-based extrudates.

Extrusion conditions were optimized through design expert using central composite rotatable design (CCRD) experimental design. The effect of feed moisture (10–22%), screw speed (215–385 rpm) and barrel temperature (95–160 °C) on specific mechanical energy (SME), bulk density (BD), water absorption index (WAI), water solubility index (WSI), expansion ratio (ER), breaking strength (BS) and instrumental color (L*, a*, b*) was evaluated.

All the system and product responses were significantly (p < 0.01) affected by independent variables. Regression models obtained were highly significant with high coefficient of determination (R² = 0.992). The optimum extrusion conditions obtained by numerical optimization for development of snacks were moisture content of 12%, screw speed of 350 rpm and temperature of 133 °C. The vitamin B₁ content of brown-rice-based snacks was 0.45 mg/100 (50% of RDA) whereas no vitamin B₁ was detected in white-rice-based snacks used as control.

The developed snacks contain 0.45 mg/100 g of vitamin B₁. If a person on an average consumes 150 g of snacks in a day, 50% of RDA (1.2 mg/day) for vitamin B₁ can be sufficed. Therefore, developed snacks can prove to be a viable vehicle to reduce the vitamin B₁ deficiency burden among the target population. Large-scale production and consumption of such type of snacks could improve the nutritional status of vitamin B1 deficient people. Furthermore, it can also provide a good opportunity for snack industry to develop nutritious snacks through utilization of brown rice.

Brown rice flour contains nutrients such as iron, calcium, zinc, sodium and vitamin B₁ in appreciable portions and was thus explored for development of nutritious snacks. Moreover, developed snacks recorded an overall acceptability of 4.70 out of 5, which depicts it is acceptable for mass production and consumption.

Keeping in view the diabetes status that has affected about 415 million people globally and is the leading cause of death in many countries along with therising demand for low Glycemic Index (GI) foods, the purpose of this paper is to optimize the extrusion process for the development of low GI snacks from underutilized crops like water chestnut and barley.

The extrusion parameters (screw speed and barrel temperature), feed moisture and water chestnut flour, barley flour proportion, were varied and their effects on system and product responses (specific mechanical energy, water absorption index, water solubility index, bulk density, expansion ratio and breaking strength) were studied.

All the system and product responses were significantly affected by independent variables. Response surface and regression models were established to determine the responses as function of process variables. Models obtained were highly significant with high coefficient of determination (R²=0.88). The optimum processing conditions obtained by numerical optimization for the development of snacks were 90°C barrel temperature, 300 rpm screw speed, 14 per cent feed moisture and WCF-to-BF ratio as 90:10. Shelf life studies confirmed that the developed snacks can be safely stored in HDPE bags for a period of six months under ambient conditions.

Water chestnut and barley flour did not blend till date for extrusion cooking. Such snacks shall be a viable food option for diabetic people and can act as laxative due to high fibre and β-glucan content from barley.