Physicochemical and nutritional properties of extrudates from food grade distiller's dried grains, garbanzo flour, and corn grits

Optimization of the extrusion parameters for the production of lentil-quinoa extrudates enriched with pumpkin

This study aimed to develop a protein-fiber-rich extruded product based on yellow lentil, quinoa, and pumpkin flours. The final product quality is affected by formulation and extrusion parameters. Therefore, the effect of the pumpkin-flour ratio (A: 25-75%) and feed moisture content (C: 14-22%) besides barrel screw speed (B: 120-180 rpm) on the physical attributes of extrudates was investigated. Box-Behnken experimental design and stepwise-response surface method were used to analyze the effects of various process variables and ingredients on extrudates. The pumpkin-flour ratio had a significant positive correlation with bulk density (BD), water solubility index (WSI), and oil absorption index. Whereas the correlation between pumpkin-flour ratio with hardness, porosity, expansion ratio (ER), and water absorption index (WAI) was negative (P < 0.05). The feed moisture content positively affected the water activity (aw) and WAI and negatively affected the harness of samples (P < 0.05). The screw speed had a positive effect on ER, porosity, and WSI, whereas it negatively influenced the hardness, BD, and aw. By increasing the pumpkin-flour ratio, air cell size and wall thickness of samples had been decreased. The results showed that 44.2% pumpkin flour, 22% feed moisture, and 172.1 rpm screw speed gave an optimized product. There was no significant difference between predicted and experimental values (except for ER). The optimized snack was a good source of fiber (around 15%), protein (17.3%), and antioxidants (TPC = 15.28 mg GAE.g-1 and antiradical scavenging activity (DPPH) = 33.66%). The caloric value of the optimized snack was 362.6 cal.100g-1. The current formulation can be considered as the base of snack food or plant-based meat alternatives.

Sustainable utilization of apple pomace and its emerging potential for development of functional foods

Apple pomace, a byproduct of apple processing industry, possesses nutritional components which are of great interests for health aspects. Apple pomace is a good source of dietary fiber, minerals, carbohydrates, phenolic, and antioxidant compounds. These bioactive compounds can be extracted by different extraction techniques which have been comprehensively described in this review article. Furthermore, the incorporation of apple pomace as functional ingredients in different food products like bakery items, extrusion-based snacks, meat, dairy, and confectionary products to improve the commercial value and health benefits has been discussed briefly. This review article can be a helpful tool for industrialists, innovative researchers, and waste management authorities to manage the apple waste in an appropriate and sustainable way.

Development, Characterization and Sensory Evaluation of an Extruded Snack Using Fig Molasses By-Product and Corn Semolina

The effects of extrusion process parameters on the physicochemical, pasting and technological properties of ready-to-eat snacks were evaluated. The aim was to develop fortified extruded products with fig molasses by-product powder (FMP), which is created as a result of the production of fig molasses, is not currently used in food industry, and may cause environmental problems. The feed humidity was changed to 14-17-20%, the die temperature was 140-160-180 °C and the ratio of FMP was 0-7-14% at a fixed screw speed of 325 rpm. The study showed that adding FMP to extruded products had a significant effect on colour properties, water solubility and water absorption index properties. İncreasing the FMP ratio had a significant reducing effect on dough properties of non-extruded mixtures such as peak viscosity (PV), final viscosity (FV) and setback viscosity (SB). The optimum conditions for the production of snacks were found to be 7% FMP, 155.44 °C die temperature and 14.69% humidity. It was determined that the estimated values of water absorption index (WAI) and water solubility index (WSI) for the products manufactured under ideal extrusion conditions were close to the obtained values, and that there was no significant difference between the estimated values of the other response variables and their actual values.

Optimizing the extrusion conditions for the production of expanded intermediate wheatgrass (Thinopyrum intermedium) products

Abstract

In this study, the effects of extrusion conditions such as feed moisture content (20%, 24%, and 28%), screw speed (200, 300, and 400 rpm), and extrusion temperature (130, 150, and 170°C) on the physical and functional properties (moisture content, expansion ratio, bulk density, hardness, water absorption index [WAI], water solubility index [WSI]) of intermediate wheatgrass (IWG) were investigated for the first time. Response surface methodology was used to model and optimize the extrusion conditions to produce expanded IWG. The model coefficient of determination (R²) was high for all the responses (0.87–0.98). All the models were found to be significant (p < 0.05) and were validated with independent experiments. Generally, all the extrusion conditions were found to have significant effects on the IWG properties measured. Increasing the screw speed and decreasing the extrusion temperature resulted in IWG extrudates with a high expansion ratio. This also resulted in IWG extrudates with generally low hardness and bulk density. Screw speed was found to have the most significant effect on the WAI and WSI, with increasing screw speed resulting in a significant (p < 0.05) decrease in WAI and a significant (p < 0.05) increase in WSI. The optimum conditions for obtaining an IWG extrudate with a high expansion ratio and WAI were found to be 20% feed moisture, 200 –356 rpm screw speed, and 130–154°C extrusion temperature.

Practical Application

Extrusion cooking was employed in the production of expanded IWG. This research could provide a foundation to produce expanded IWG, which can potentially be used as breakfast cereals and snacks. This is critical in the efforts to commercialize IWG for mainstream food applications.

Something to chew on: technological aspects for novel snacks

Snacks have accompanied people for a long time, meeting our needs for something fast and filling between meals. Societies and technologies have changed, and so have snacks, adapting to people's daily lives, concerns, and demands. Although traditional snacks, such as potato chips, are still ubiquitous and popular worldwide, there is not unanimity around them anymore, since many people have been looking for healthier snacks. Studies have been carried out to propose healthier snack options by changing their composition and/or techniques to produce them, minimizing contents of energy-dense components and/or maximizing the retention or bioavailability of nutrients. This mini-review presents the main trends on development of snacks and future perspectives. © 2021 Society of Chemical Industry.

Germinated chickpea-maize extrudates with high protein content and reduced starch digestibility

The objective of this study was to produce maize extrudates supplemented with germinated chickpea flour to increase the contents of resistant starch (RS) and protein. Six extrudates were formulated using maize grits (ME), germinated chickpea flour (GCE) and different blends of maize and 10%, 20%, 30%, or 40% of germinated chickpea flour (MGCE-10, MGCE-20, MGCE-30, or MGCE-40). Increase of RS was observed in the defatted samples due to germinated chickpea flour addition. In the nondefatted samples, the highest content of RS was observed in GCE followed by ME and the different MGCE. Interaction between fat, starch, and protein by improved intramolecular association was assessed by Fourier transform- infrared spectroscopy (FTIR). Amylose-lipid complexes in nondefatted samples increased the content of RS in comparison to defatted samples. The highest expansion index was obtained in MGCE-30 and MGCE-40. ME had the highest hardness and crispiness. Germinated chickpea flour increased the water absorption index (WAI), but reduced water solubility index (WSI) when it was combined with maize grits to produce extrudates. The in vitro protein digestibility (IVPD) was higher in the GCE and MGCE with more than 20% of germinated chickpea flour compared to ME. MGCE-20 and MGCE-30 showed the highest acceptability of the supplemented extrudates with 50% more protein than ME, a similar IVPD to that of GCE, and good functional characteristics. PRACTICAL APPLICATION: Combining maize and germinated chickpea flour is a good strategy to have a controlled digestibility of starch and increase the plant based protein content in healthier snacks.

Gluten-Free Rice Instant Pasta: Effect of Extrusion-Cooking Parameters on Selected Quality Attributes and Microstructure

In the present study, we applied extrusion-cooking to polished rice flour so as to prepare gluten-free pasta. The aim of the work was to investigate the effect of feed moisture (28, 30 and 32%) and screw speed (60, 80 and 100 rpm) on selected rice pasta quality attributes (water absorption, cooking loss, firmness, stickiness and microstructure) and extrusion response (specific mechanical energy). Our results showed that feed moisture significantly affected all tested quality attributes of the rice pasta, while screw speed exhibited a significant effect on all quality attributes except cooking time and stickiness. Moreover, raising the feed moisture increased the cooking time, water absorption, cooking loss, hardness and stickiness, but decreased the firmness at high screw speed. In addition, increasing the screw speed enhanced the cooking loss and hardness, but diminished the water absorption and firmness of pasta with low feed moisture. Rice pasta prepared with 30% moisture content and at 80 rpm showed adequate quality, as confirmed by a firm texture and low cooking loss and stickiness. Microstructure analysis showed a compact and dense internal structure of the dry pasta, and the surface was smooth and even when at least 30% moisture was applied at 80 rpm screw speed during processing.

Effects of corn distillers dried grains on dough properties and quality of Chinese steamed bread

Chinese steamed bread (CSB) accounts for 30% of the wheat end-use in China. CSB was studied as a platform for fiber and protein enrichment, employing corn distillers dried grains. Food grade distiller's grain (FDDG) processed from co-products from the corn ethanol industry was used as the enrichment ingredient. Since CSB uses a lean formula with little or no added sugar or fat, it relies entirely on fermentation and steaming for flavor and texture development. FDDG was used to replace 0%-25% all-purpose flour (APF) in CSB formulations. Effects of FDDG on dough properties and quality of CSB were evaluated by instrumental (Farinograph, Mixolab, and Texture Analyzer), nutritional, and sensory methods. Protein and dietary fiber contents showed significant increases to 18.8% and 15.3%, respectively, for 100 g of steamed bread (25% FDDG db). Fiber in 100 g of fresh FDDG CSB ranged from 2.8 to 7.7 g. FDDG fortified doughs demonstrated higher water absorption, while dough development time, dough stability, and dough extensibility decreased significantly with partial APF replacement. FDDG contributed to increased hardness and adhesiveness in the CSB. Crumb analysis revealed reduced number of gas cells at higher FDDG substitution. FDDG enrichment reduced brightness (L*) of flour blends and CSB. Rheological and sensory analysis showed an upper level of FDDG substitution of 15% was acceptable without detriment to dough functionality, texture, and taste.

Purification of Polyphenols from Distiller's Grains by Macroporous Resin and Analysis of the Polyphenolic Components

We aimed to purify polyphenols from distiller’s grain extract using macroporous resins and to identify its polyphenolic components. The influence of operational parameters on purification efficiency was investigated. The polyphenolic composition was analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and then quantified by UPLC-MS using authenticated standards. The results showed that the optimal purifying conditions were D101 resin with a dosage of 3 g, four hours adsorption, three hours desorption time, and 60% ethanol as the eluent, producing the highest purification rate of 51%. The purified distiller’s grain extract exhibited stronger antioxidant activity than the unpurified extracts, which was assessed using DPPH and ABTS methods (IC₅₀ DPPH = 34.03 and 16.21 μg/mL, respectively; IC₅₀ ABTS = 20.31 and 5.73 μg/mL, respectively). UPLC-MS results indicated that (−)-epicatechin is the major compound found in distiller’s grain extract which was quantified as 562.7 μg/g extract, followed by ferulic acid (518.2 μg/g), p-hydroxybenzoic acid (417.7 μg/g), caffeic acid (217.1 μg/g), syringic acid (158.0 μg/g) and quercetin (147.8 μg/g). Two compounds, vanillic acid (66.5 μg/g) and gallic acid (41.4 μg/g), were found in lower concentrations. The findings of this study suggest that purification of polyphenolic compounds from distiller’s grain by macroporous resins is feasible, providing a new and effective method for the secondary use of distiller’s grain resources.

Effect of chickpea and spinach on extrusion behavior of corn grit

The present work was carried out to see the effect of blending of corn grit (CG) with varying levels of chickpea grit (CP 0-100%) and spinach leaf powder (SP 0-6%) on the characteristics [color, expansion, density, hardness, water absorption index, total phenolic content (TPC), antioxidant activity (AOA; as DPPH and ABTS free radical scavenging activities)] and sensory properties of extrudates. CP and SP were rich in proteins and minerals (Cu, Fe, Zn, Mg, Ca, K and Na). Their blending significantly influenced the physicochemical and antioxidant properties of CG extrudates. TPC and AOA of extrudates increased with the increased incorporation of CP and SP, though specific mechanical energy and extrudate expansion, generally, decreased while density and hardness increased. Sensory analysis revealed that CP and SP at incorporation levels of 25% and 4%, respectively could be blended with CG for making highly acceptable antioxidant-rich expanded snack.