Evaluation of the physicochemical properties of third-generation snacks made from blue corn, black beans, and sweet chard produced by extrusion

Extrusion of decoction residues of Roselle (Hibiscus sabdariffa L.) with different starchy wall materials retaining the polyphenol content after in vitro digestion

Decoction residues (DR) of Roselle are a waste with high polyphenol content. The remaining polyphenols are resistant to thermal treatments and have antioxidant properties. An alternative for the use of the DR is the extrusion with wall material that can preserve the antioxidant capacity of the polyphenols. The present study aimed to produce a functional ingredient with the Roselle DR by extrusion with different commercial starchy wall materials (Capsul, N-Lok, and Globe). The extrudates were analyzed for morphology, bioaccessibility of polyphenols, antioxidant capacity (AC), and starch digestion rate. The confocal microscopy showed the presence of fiber with polyphenols. The extruded with Capsul and Globe showed the highest slowly digestible starch (SDS) and resistant starch (RS) content. The bioaccessibility of polyphenols was higher in the Capsul and Globe extrudates indicating gradual release during the intestinal digestion. Capsul and Globe showed the best results in protecting the polyphenols.

Effects of the extrusion conditions, the addition of oil and the food matrix on the physical and sensory characteristics of pre-extrusion flavored products

Thermoplastic extrusion is important in processing a wide variety of food products. In this paper, the effects of different extrusion conditions, addition of vegetable oil and the food matrix itself on the physical and sensory characteristics of corn snacks and meat analogs were evaluated. Cysteine and butyric acid (cheese aroma precursors) and thiamine (a meat aroma precursor) were added to corn grits and soy protein concentrate, respectively, before extrusion. For each matrix, three combinations of moistures of the raw material and extrusion temperatures were used and, after extrusion, vegetable oil was added to one portion of each product and not to another one. The extrusion conditions and the addition of oil affected the physical properties and sensory characteristics of corn snacks more while they had less influence on the properties of the meat analogs. There were similar correlations between the physical and sensory variables, independent of the food matrix used. The sensory acceptance stood out for samples from intermediate and less severe extrusion conditions and with added oil, showing that these factors have an impact on the physical properties and sensory characteristics, with little effect from the food matrix.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-05985-3.

The Development of Novel Functional Corn Flakes Produced from Different Types of Maize (Zea mays L.)

Cereal products, such as flakes and snack items, are frequently consumed as part of everyday diets, encompassing ready-to-eat breakfast cereals, flakes, and snacks. The utilization of extrusion technology is crucial in the manufacturing process of cereal-based flakes or snack products. When it comes to cereal-based flakes or snacks, different types of corn, such as white corn, yellow corn, red corn, and black corn, have garnered attention from scientists, consumers, and experts in the food industry. This paper investigates the simultaneous effects of different types of corn (white corn, yellow corn, red corn, and black corn) addition and different screw speeds (350, 500, 650 rpm) on the physical, technological, and functional properties of flake products. An increasing screw speed had a positive influence on the physical and technological characteristics of corn flakes, while different types of corn had a positive influence on the mineral composition and antioxidant properties. Black corn flour and a screw speed of 350 rpm positively influenced the physical and technological characteristics, mineral composition, and antioxidant properties of flake products, with a best total Z-score analysis of 0.59. Overall, the combination of Tukey's HSD test and PCA enabled a comprehensive analysis of the observed corn products and allowed us to identify satiating and significant differences between attributes and create a classification of the samples based on those differences. Corn flakes from black corn flour on a screw speed of 350 rpm is a new product with good physical-technological and functional properties due to a higher level of antioxidant activity. The last three samples have a significantly higher percentage of free radical inhibition compared with the other samples according to TPC and TFC. This product has the potential to be found on the market as a new product with functional properties.

Effect of the Addition of Soybean Residue (Okara) on the Physicochemical, Tribological, Instrumental, and Sensory Texture Properties of Extruded Snacks

An extrusion process was used to improve the physical and textural characteristics of an extruded snack supplemented with soybean residue (okara). An extreme vertices mixture design with a constraint for okara flour (0−50%), mung bean flour (20−70%), and rice flour (20−80%) resulted in the production of eleven formulations. The color, radial expansion index (REI), bulk density, tribological behavior, and instrumental and sensory texture of the extruded snacks were evaluated. Increasing the quantity of okara resulted in an extrudate with a darker, redder color, decreased REI, increased bulk density, and decreased crispness. The tribological pattern of the snack was determined by its dominant composition (protein, starch, or fiber) in the flour mixture, which contributed to the stability of the lubricating film under rotational shear. A principal component analysis of sensory data captured a total of 81.9% variations in the first two dimensions. Texture appeal was inversely related to tooth packing (r = −0.646, p < 0.05). The optimized formulation for texture preference had an okara content of 19%, which was 104% crispier and 168% tougher than an okara content of 40%. This by-product of soybean milk processing can thus be used to develop gluten-free snacks with desirable physical characteristics and texture.

Assessment of the Nutritional Value of Traditional Vegetables from Southern Chile as Potential Sources of Natural Ingredients

There is an increasing interest in consuming healthy foods motivated by the need of boosting the immune system naturally. In this sense, vegetables rich in bioactive compounds are a clear example of "superfoods" that promotes overall health and strengthen the immune response. Therefore, in this study eight traditional vegetables usually produced in southern Chile (pea, corn, carrot, leek, spinach, chard, coriander and parsley) were characterized in terms of their nutritional composition to evaluate their potential as lyophilized natural ingredients. Thus, chemical composition, amino acid profile, minerals, vitamins, carotenoids, polyphenols and pesticide residues were evaluated. Green leafy vegetables resulted to be an excellent source of proteins and dietary fibers as well as vitamins (ascorbic acid, choline, alpha-tocopherol and niacin), minerals (calcium, phosphorus and iron), carotenoids and polyphenols. Among the eight vegetables assessed spinach exhibited the more balanced nutritional profile. Moreover, 332 pesticide residues were analysed and only six were detected in a low concentration. Due to their nutritional properties, the present results suggest that vegetables produced in southern Chile could be considered as promising alternatives to develop natural food ingredients.

Anthocyanins and Functional Compounds Change in a Third-Generation Snacks Prepared Using Extruded Blue Maize, Black Bean, and Chard: An Optimization

The effect of extrusion cooking on bioactive compounds in third-generation snacks (TGSE) and microwave-expanded snacks (MWSE) prepared using black bean, blue maize, and chard (FBCS) was evaluated. FBCS was extruded at different moisture contents (MC; 22.2–35.7%), extrusion temperatures (ET; 102–142 °C), and screw speeds (SP; 96–171 rpm). Total anthocyanin content (TAC), contents of individual anthocyanins, viz., cyanidin-3-glucoside, malvidin-3-glucoside, pelargonidin-3-glucoside, pelargonidin-3-5-diglucoside, and delphinidin-3-glucoside chloride, total phenolic content (TPC), antioxidant activity (AA), and color parameters were determined. TAC and individual anthocyanin levels increased with the reduction in ET. ET and MC affected the chemical and color properties; increase in ET caused a significant reduction in TPC and AA. Microwave expansion reduced anthocyanin content and AA, and increased TPC. Extrusion under optimal conditions (29% MC, 111 rpm, and 120 °C) generated products with a high retention of functional compounds, with high TAC (41.81%) and TPC (28.23%). Experimental validation of optimized process parameters yielded an average error of 13.73% from the predicted contents of individual anthocyanins. Results suggest that the TGSE of FBCS obtained by combining extrusion and microwave expansion achieved significant retention of bioactive compounds having potential physiological benefits for humans.