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The technological quality of the protein fraction of wheat white flour (WW) was determined by the lactic acid Solvent Retention Capacity and by the Gluten Performance Index (LA-SRC and GPI; AACC method 56-11.01). Parallelly, Perten's standard Gluten Index test (GI; AACC method 38-12.02) was performed with that wheat control. Consequently, the same methods were applied to 9 bi-composite blends mixed at ratios of 90 : 10, 80 : 20, 70 : 30, 60 : 40, 50 : 50, …, and 10 : 90 as WW replacement with one of the rye bread flours (RB), and the RB control itself. Unlike successful measurements in the case of the LA-SRC and GPI, washing gluten from the first 90 WW : 10 RB blend led to the clogging of the Glutomatic sieve, likely due to the interaction of wheat gluten with rye arabinoxylans. The discrepancy induced the development of a modification of the standard GI procedure; clogging was avoided by precipitating flour and centrifuging the swollen solid from suspension, similarly like in the SRC method. The settled residue transported to a standard sieve cassette was secondly centrifuged in the original apparatus Perten CF2015. The weighing of the overflow and underflow of the sieve and the calculation of the results were performed according to the original GI method. For the WW control, the standard GI value was 90% and the modified Gluten Index value (GImodif) was 82%. As expected for WW-RB counterparts, the higher the portion of rye in the bi-composite blend, the lower the value of the GImodif . For the 50 WW : 50 RB blend and the RB itself, the GImodif values were 47% and 18% (the GPI values 0.66, 0.45, and 0.39, respectively). On the contrary, the LA-SRC demonstrated a convex course (118, 104, and 123%, respectively). In the plane of the principal components (PC), namely PC1 and PC2, the variables related to gluten quality formed 4 groups as a function of the stepwise change in the mixing ratio of WW and RB: i) flour protein content, GPI, and GImodif ; ii) LA-SRC; iii) dietary fibre content and ash content; iv) water, sucrose, and sodium carbohydrate SRCs. However, the modified test procedure should be revised in wheat varieties characterised by a wider spectrum of protein quality, mixed with different types of rye flour (especially wholegrain one).

The aim of the paper was to seek optimum conditions of extrusion cooking and follow-up processing to produce high-quality tortillas with good sensory properties. Sixteen samples of maize flour were prepared by extrusion with and without alkaline treatment. The extrudate diameters depended primarily on the moisture content of the premix and the temperature in the extruder. Alkaline treatment with calcium hydroxide [Ca(OH)2] had a strong effect on water absorption index (WAI), water solubility index (WSI), pH, and colour of the extrudates. Besides, WAI was influenced by the moisture of the premix and by the temperature in the second zone of the extruder. Soluble dietary fibre (SDF) in the samples with the addition of Ca(OH)2 increased more than in the samples without alkaline treatment. In addition, a higher screw speed influenced SDF. The texture of the tortillas was very dependent on the addition of Ca(OH)2, on the moisture of the premix and the temperature in the second zone of the extruder.

This review paper focuses on the recent advancements in the large-scale and laboratory-scale isolation, modification, and characterization of novel starches from accessible botanical sources and food wastes. When creating a new starch product, one should consider the different physicochemical changes that may occur. These changes include the course of gelatinization, the formation of starch–lipids and starch–protein complexes, and the origin of resistant starch (RS). This paper informs about the properties of individual starches, including their chemical structure, the size and crystallinity of starch granules, their thermal and pasting properties, their swelling power, and their digestibility; in particular, small starch granules showed unique properties. They can be utilized as fat substitutes in frozen desserts or mayonnaises, in custard due to their smooth texture, in non-food applications in biodegradable plastics, or as adsorbents. The low onset temperature of gelatinization (detected by DSC in acorn starch) is associated with the costs of the industrial processes in terms of energy and time. Starch plays a crucial role in the food industry as a thickening agent. Starches obtained from ulluco, winter squash, bean, pumpkin, quinoa, and sweet potato demonstrate a high peak viscosity (PV), while waxy rice and ginger starches have a low PV. The other analytical methods in the paper include laser diffraction, X-ray diffraction, FTIR, Raman, and NMR spectroscopies. Native, “clean-label” starches from new sources could replace chemically modified starches due to their properties being similar to common commercially modified ones. Human populations, especially in developed countries, suffer from obesity and civilization diseases, a reduction in which would be possible with the help of low-digestible starches. Starch with a high RS content was discovered in gelatinized lily (>50%) and unripe plantains (>25%), while cooked lily starch retained low levels of rapidly digestible starch (20%). Starch from gorgon nut processed at high temperatures has a high proportion of slowly digestible starch. Therefore, one can include these types of starches in a nutritious diet. Interesting industrial materials based on non-traditional starches include biodegradable composites, edible films, and nanomaterials.

Phenolic compounds are linked to a number of health benefits, including antioxidant, antibacterial, antiglycaemic, antiviral, anticarcinogenic, anti-inflammatory and vasodilatory properties. To improve a great loss of phenolics during extrusion, researchers have investigated incorporating functional ingredients into the extrusion input mixture. Other reasons for the addition of active ingredients are the re-use of by-products from food technology, decreasing the calorie content of extruded food, inhibition of starch digestion, and the colour change of the gluten-free products. The paper presents 28 examples of new designs for extrusion based on rice, corn, cassava, sorghum, and lentil flours and on other crops, together with the analyses of phenolics. The present results show the highest total phenolic content in sorghum among cereals, and lentil flour and orange peel powder among mixtures for extrusion to prepare extrudates. The highest content of total flavonols was found in the mixture containing corn and freeze-dried red and purple potatoes.

Resistant starch (RS), which is inaccessible to human digestive enzymes, is fermented in the colon, producing short-chain fatty acids which have beneficial effects on the human health. Both laboratory-prepared acetylated starch (AS) (degree of substitution 0.82) and Hi-maize commercial starch were tested as additives to bread formulations (recipes). The quality of composites prepared from commercial wheat flour and 5-25% of the added starch was identified by an RVA analyser and the Mixolab rheological test. The bread volume, stiffness (durability), and sensory parameters were evaluated. The addition of 15% Hi-maize® caused a worse appearance, lower volume, and a light colour of the crust. On the other hand, it increased RS content to 5%. The substitution of 5% wheat flour with AS proved to be the most suitable, as the bread was highly appraised by consumers, the retrogradation of starch decreased, and RS content was 2.4%, approximately twice that of the bread without any starch addition.

A laboratory single-screw Kompaktextruder KE 19/25 was used at speeds 120-140 rpm of the screw with either a 2 : 1 or 3 : 1 compression ratio; the head had a 3 or 4 mm die. The temperature of the head was set at 131-144°C. The applied raw materials were maize grits, and mixtures with wheat starch, pea flour or chemically modified starch. Input mixtures differed in water addition (50 or 100 g water/kg). The highest amount of resistant starch (3.1% per total starch) in extrudate was found for mixture of pea flour and maize grits (with addition of 100 g water/kg of dry mixture), the output(extrudate)/input(mixture) ratio of the resistant starch was 45.8%. The highest SDS content was obtained for the maize grits and addition of 100 g water/kg using a die with a 3 mm diameter and a screw with a 3 : 1 compression ratio; the temperature of the head was approximately 140°C. Transportation rates: screw 140 rpm, dosing 15 rpm.