The influence of extrusion process with a minimal addition of corn meal on selected properties of fruit pomaces

Development of composite electrospun films utilizing soy protein amyloid fibrils and pullulan for food packaging applications

Electrospun films (ESF) are gaining attention for active delivery due to their biocompatibility and biodegradability. This study investigated the impact of adding soy protein amyloid fibrils (SAFs) to ESF. Functional ESF based on SAFs/pullulan were successfully fabricated, with SAFs clearly observed entangled in the electrospun fibers using fluorescence microscopy. The addition of SAFs improved the mechanical strength of the ESF threefold and increased its surface hydrophobicity from 24.8° to 49.9°. Moreover, the ESF demonstrated antibacterial properties against Escherichia coli and Staphylococcus aureus. In simulated oral disintegration tests, almost 100% of epigallocatechin gallate (EGCG) dissolved within 4 min from the ESF. In summary, the incorporation of SAFs into ESF improved their mechanical strength, hydrophobicity, and enabled them to exhibit antibacterial properties, making them promising candidates for active delivery applications in food systems. Additionally, the ESF showed efficient release of EGCG, indicating their potential for controlled release of bioactive compounds.

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.

Quality Characteristics of Novel Pasta Enriched with Non-Extruded and Extruded Blackcurrant Pomace

Fruit pomace is a valuable by-product in terms of its chemical composition, which potential might be used through transformation of the pomace into food ingredients. The aim of this work was to assess the effect of partial (5% and 10%) substitution of powdered non-extruded or extruded blackcurrant pomace for semolina in pasta formula on nutritional and technological properties of the final product. The pasta was assessed for chemical composition, DPPH antiradical activity, color, cooking and textural properties. Presence of the by-products in the pasta resulted in increased total dietary fiber content (from 1.89 ± 0.06 up to 10.03 ± 0.15 g/100 g, dwb), fat content (from 1.29 ± 0.01 up to 2.70 ± 0.05 g/100 g, dwb) and DPPH antiradical activity (from 253 ± 15 up to 1037 ± 7 µmol TE/g, dwb), as well as in significantly different color (p < 0.05) as compared to the semolina-only pasta. The optimal cooking time was shortened by 1.0−1.5 min and by 2.0 min in the case of the lower and higher, respectively, level of pasta supplementation. The water absorption decreased by up to 32% in the enriched pasta. In general, the cooking loss remained unchanged. The uncooked product containing the extruded fruit pomace was characterized by significantly higher breaking strength (p < 0.05) as compared to the standard pasta. Presence of the pomace also affected texture of the cooked pasta, increasing its firmness and hardness and, when using the non-extruded pomace, the tensile strength. In our research, we have shown that durum wheat pasta enriched with 5 or 10% of powdered blackcurrant pomace or their extrudates constitute a food product of improved nutritional value and of appropriate textural characteristics, while maintaining culinary properties that meet pasta industry requirements.

Thermo-mechanical processing of fibre-rich blackcurrant pomace to modify techno-functional properties

Exploring the use of seedless blackcurrant pomace, a fibre-rich by-product of juice pressing, in foods is favourable due to its nutritional profile but also for economic and sustainability aspects. Current applications are limited to products in which rapid fibre swelling, high water solubility or low sedimentation is not essential. In this study, functional properties of seedless blackcurrant pomace were modified by thermo-mechanical treatments using extrusion cooking or micronization in a planetary ball mill. A full factorial design showed that low pomace moisture (11 g/100 g) had the highest impact on swelling capacity (+ 20.6%) and water solubility index (+ 23.2%), whereas variation in extrusion temperature exhibited only minor effects. After milling for 4 h, the median particle size was reduced by 98% to 4 µm and the specific surface area increased from 0.1 to 2.5 m2/mL. Swelling capacity was highest after this time with 7.6 mL/g pomace and, although the amount of extractable sugars was reduced, water solubility increased to 7.6 g/100 g. In contrast to extruded samples, the red colour of the pomace was intensified after milling. Both treatments appear as promising to extend the applicability of fruit by-products in foods, as micronized pomace may counteract sedimentation in liquids, whereas increased swelling capacity after extrusion may have stabilizing effects on yoghurt-like systems.