A Review of the Changes Produced by Extrusion Cooking on the Bioactive Compounds from Vegetal Sources

The demand for healthy ready-to-eat foods like snacks is increasing. Physical modification of vegetal food matrices through extrusion generates significant changes in the chemical composition of the final product. There is a great variety of food matrices that can be used in extrusion, most of them being based on cereals, legumes, fruits, vegetables, or seeds. The aim of this review was to summarize the main effects of the extrusion process on the bioactive compounds content, namely phenolics, terpenes, vitamins, minerals, and fibers of vegetal mixes, as well as on their biological activity. The literature reported contradictory results regarding the changes in bioactive compounds after extrusion, mainly due to the differences in the processing conditions, chemical composition, physicochemical properties, and nutritional value of the extruded material and quantification methods. The thermolabile phenolics and vitamins were negatively affected by extrusion, while the fiber content was proved to be enhanced. Further research is needed regarding the interactions between bioactive components during extrusion, as well as a more detailed analysis of the impact of extrusion on the terpenes since there are few papers dealing with this aspect.

Combined Thermomechanical-Biological Treatment for Corn By-Product Valorization into Added-Value Food (Feed) Material

The aim of this study was to apply the combined thermomechanical-biological treatment for corn processing by-product (CPBP) valorization to added-value food and feed material. The mechanical-thermal pre-treatment was performed by applying the extrusion technique. Extruded CPBPs (14, 16, and 18% moisture) were further biodegraded with Lactiplantibacillus plantarum-LUHS122 (Lpl), Liquorilactobacillus uvarum-LUHS245 (Lu), Lacticaseibacillus casei-LUHS210 (Lc), and Lacticaseibacillus paracasei-LUHS244 (Lpa). Acidity parameters, microbial characteristics, sugars concentration, amino and fatty acids profile, biogenic amines (BA), and antibacterial and antifungal properties of CPBP were analyzed. Fermented CPBP had a reduced count of mould/yeast. A significantly lower (p ≤ 0.05) count of total enterobacteria was found in most of the extruded-fermented CPBP. Fermentation of extruded CPBP (moisture of 16 and 18%) increased valine and methionine content. Cadaverine and spermidine were not found after treatment of CPBP, and the lowest content of BA was found in the extruded-fermented (Lpa, moisture 18%) CPBP. Applied treatment had a significant effect on most of the fatty acids. CPBP fermented with Lpl, Lu, and Lpa displayed inhibition properties against 3 of the 10 tested pathogenic/opportunistic bacterial strains. Extruded-fermented (Lu, Lc, and Lpa moisture of 14 and 18%) CPBP showed antifungal activity against Rhizopus. Extruded-fermented (14% moisture, Lpl) CPBP inhibited Rhizopus and Aspergillus fumigatus. In conclusion, combined treatment can improve certain parameters and properties of CPBP in order to produce safer and more nutritious ingredients for food and feed industries.

Utilization of Amaranthus spp. grains in food

Recently there has been a rediscovery of some ancient crops due to increased consumer demands for a healthier diet with medicinal and therapeutic effects. One such crop is a pseudocereal Amaranthus sp., which is nutritionally more favourable than many widespread kinds of cereal and meets most of the requirements of modern diets. The incorporation of amaranth species in food formulations would expand the assortment of food products present on the market. The high nutritional quality and potential functionality of amaranth-based food products have been the subject of extensive scientific research. This study aims at reviewing the currently available data on the application of amaranth grains in the food industry and manufacturing and focuses on the functionalities of these products, providing an overview of the current amaranth value chain.

Utilization of Amaranthus spp. grains in food

Recently there has been a rediscovery of some ancient crops due to increased consumer demands for a healthier diet with medicinal and therapeutic effects. One such crop is a pseudocereal Amaranthus sp., which is nutritionally more favourable than many widespread kinds of cereal and meets most of the requirements of modern diets. The incorporation of amaranth species in food formulations would expand the assortment of food products present on the market. The high nutritional quality and potential functionality of amaranth-based food products have been the subject of extensive scientific research. This study aims at reviewing the currently available data on the application of amaranth grains in the food industry and manufacturing and focuses on the functionalities of these products, providing an overview of the current amaranth value chain.

Recent developments and knowledge in pseudocereals including technological aspects

Amaranth, buckwheat, quinoa, and less known, canihua are the most important pseudocereals. Their high nutritional value is well recognized and they are increasingly used for the development of a wide range of starch-based foods, which has been fostered by intensified research data performed in recent years. In addition to health driven motivations, also environmental aspects like the ongoing climate change are an important stimulus to increase agricultural biodiversity again. As pseudocereals are botanically classified as dicotyledonous plants their chemical, physical and processing properties differ significantly from the monocotyledonous cereals. Most important factors that need to be addressed for processing is their smaller seed kernel size, their specific starch structure and granule architecture, their gluten-free protein, but also their dietary fibre and secondary plant metabolites composition. This review gives a condensed overview of the recent developments and gained knowledge with special attention to the technological and food processing aspects of these pseudocereals.

Effect of Medicago sativa Addition on Physicochemical, Nutritional and Functional Characteristics of Corn Extrudates

Currently, extrudates are considered unhealthy products, being characterized as high in calories; rich in fat, sugar, and salt; and low in nutritional compounds. The aim of this study was to assess the influence of lucerne (Medicago sativa) on the physicochemical, nutritional, and functional characteristics of corn extrudates. In order to achieve these goals, water content, water activity, expansion index, bulk density, porosity, hygroscopicity, optical properties, antioxidant activity, individual phenolic acids, folates, individual flavonoids, and volatile compounds were analyzed. The results showed that the typical characteristics of corn extrudates such as expansion, crunchiness, and density were maintained with 10% lucerne addition, highlighting a strong negative Pearson correlation (p < 0.05) between all studied parameters and lucerne addition. On the other hand, the lucerne addition caused a linear increase of bioactive compounds, showing positive Pearson correlations between flavonoids, folates, and antioxidant activity. The volatile profile of corn extrudates improved with the addition of lucerne leading to volatile compounds such as limonene, β-mircene, and hexanal. Overall, considering the textural, nutritional, and functional characteristics of corn extrudates, we determined that a percentage addition on 10% lucerne could be successfully used in the manufacturing of corn extrudates.

Characterizing the Rheological and Bread-Making Properties of Wheat Flour Treated by "Gluten FriendlyTM" Technology

After discovering an innovative technology for the reshaping of gluten proteins—the “Gluten Friendly^TM” system—that confers to wheat flour some unprecedented characteristics, such as reduced epitope antigenicity and a positive modulation of the gut microbiota, its effects on the production and quality of bread have been studied. Mainly, we have investigated the chemical, rheological and pasting properties of Gluten Friendly Flour (GFF) and of control flour (CF) with the aim of analyzing and interpreting potential differences. Furthermore, the bread made from GFF and CF was evaluated in terms of microstructure properties and sensory quality. The experiments demonstrated that GFF became soluble in aqueous solution, making it unfeasible to isolate using the Glutomatic apparatus. Although the water absorption of GFF increased by 10% compared to CF, dough elasticity was reduced, and dough stability decreased from 5 to 2 min. A significant increase in the alveograph index (P/L) from 0.63 to 6.31 was detected, whereas pasting properties did not change from the control flour. Despite these profound modifications in the rheological properties, GFF exhibited a high ability to shape dough and to produce bread with high quality and negligible differences from the control bread in terms of appearance, taste, aroma, color and texture.

Reducing the damage of quinoa saponins on human gastric mucosal cells by a heating process

Different food processing methods will influence the structure and activity of compounds. In this work, molecular structure and different content crude saponins that were extracted from quinoa, treated with water soaking, water boiling, and water steaming were analyzed by HPLC. Flow cytometry was employed to investigate the effects of the main saponins on the GES-1 cell line. HPLC/MS analysis revealed that water soaking induced an extensive conversion of polar saponin Qc (424.41 ± 21.11 mg/g) to the less polar compound Qf (247.04 ± 15.71 mg/g). After treatment with 100 μg of Qf instead of Qc for 24 hr, the percentage of dead cells increased from 20.1 ± 2.2% to 86.2 ± 4.8%. One major reason of this result is that less polar saponins could damage membrane integrity more easier than polar saponins. The results indicate that saponin toxicity is enhanced after degradation, so it is necessary to avoid degradation before use.