Sprouting Time Affects Sorghum (Sorghum bicolor [L.] Moench) Functionality and Bread-Baking Performance

Recent advances in germinated cereal and pseudo-cereal starch: Properties and challenges in its modulation on quality of starchy foods

Germination is an environmentally friendly process with no use of additives, during which only water spraying is done to activate endogenous enzymes for modification. Furthermore, it could induce bioactive phenolics accumulation. Controlling endogenous enzymes' activity is essential to alleviate granular disruption, crystallinity loss, double helices' dissociation, and molecular degradation of cereal and pseudo-cereal starch. Post-treatments (e.g. thermal and high-pressure technology) make it possible for damaged starch to reassemble towards well-packed structure. These contribute to alleviated loss of solubility and pasting viscosity, improved swelling power, or enhanced resistant starch formation. Cereal or pseudo-cereal flour (except that with robust structure) modified by early germination is more applicable to produce products with desirable texture and taste. Besides shortening duration, germination under abiotic stress is promising to mitigate starch damage for better utilization in staple foods.

Effect of water content on gelatinization functionality of flour from sprouted sorghum

Sorghum starch granules are encapsulated in a rigid protein matrix that prevents the granules from fully swelling and gelatinizing. Sprouting and subsequent drying treatment can affect the gelatinization properties of sorghum starch. This study aimed to evaluate the gelatinization properties of flours from unsprouted (US) and sprouted (S50, S40) sorghum dried at 50 °C (6h) and 40 °C (12h), respectively. Swelling power (Sp), thermal properties (DSC) and 1H molecular mobility and dynamics were evaluated at different water contents (38-91%). Sp increased with increasing water content, with S40 showing the lowest values, probably due to prolonged amylase activity and thus starch breakdown. Sprouting increased gelatinization temperatures; however, these differences disappeared for high water contents (82 and 91%). From a molecular point of view, sprouted samples showed a decrease in protons associated to the rigid protein matrix and starch structures. 1H CPMG results showed the presence of 4 populations at 38% water content. The evolution of the more mobile population with increasing water content supported the assignment of more mobile water fraction to this population. Sprouting decreased the mobility of populations in unheated samples, suggesting an increase in molecular bonds between flour biopolymers and water. After heating, however, increased molecular mobility in S40 indicated the formation of a weaker network between starch, protein, and water at the molecular level. These results suggest that post-sprouting drying treatment influences sorghum gelatinization, with potential modulation by water content. This study contributes to understanding the application of sprouted sorghum in foods with different moisture content.

Investigating sorghum protein solubility and in vitro digestibility during seed germination

In this work, we examined the impact of sorghum gain germination on kafirins solubility and digestibility. Two genotypes differing in their proteins and tannins contents were germinated under controlled conditions up to radicle emergence. Biochemical, physicochemical, and in vitro digestibility tests were applied on the germinated grains. Microscopic examination of grains endosperm revealed that germination resulted in pitted starch granules and protein matrix slackening. Apart cystine and the amount of free thiol groups which increased significantly, the overall amino acids composition remained rather unchanged, just as the kafirins solubility and size distribution. In contrast germination was demonstrated to improved significantly the in vitro protein digestibility, even after cooking and especially for the genotype poor in tannin. Without inducing major physicochemical changes, germination enhanced kafirins susceptibility to gastrointestinal proteases. Germination may be a way to improve the nutritional value of sorghum.

Sorghum Flour and Sorghum Flour Enriched Bread: Characterizations, Challenges, and Potential Improvements

A Sorghum flour (SF) is a leading and prominent food source for humans in African countries. Recently extensive studies have been conducted on Sorghum bread (SB) or sorghum composite bread (SCB), covering various aspects. However, there are many technical challenges in the formation of SF and sorghum composite flour (SCF) that impact the quality of the bread and fail to meet the consumer's desires and expectations. This review primarily focuses on the characteristics of SF, SCF, SB, and SCB, with discussions encompassing the rheological and morphological properties of the dough, improvement strategies, and bread quality. Moreover, a comprehensive analysis has been conducted to investigate the behavior of SF and SCF along with a discussion of the challenges affecting bread quality and the strategies applied for improvement. The significant demand for nutrients-rich and gluten-free bread indicates that sorghum will become one of the most vital crops worldwide. However, further comprehensive research is highly demanded and necessary for an in-depth understanding of the key features of SF and the resulting bread quality. Such understanding is vital to optimize the utilization of sorghum grain in large-scale bread production.

Suitability of Improved and Ancient Italian Wheat for Bread-Making: A Holistic Approach

Ancient and old wheat grains are gaining interest as a genetic reservoir to develop improved Italian genotypes with peculiar features. In this light, the aim of this study was to assess the baking performance of two improved einkorn (Monlis and Norberto) and two improved emmer (Padre Pio and Giovanni Paolo) genotypes in comparison with two Italian landraces (Garfagnana and Cappelli) and Khorasan. This set was evaluated following a holistic approach considering the flour, dough, and bread properties. The results showed that the flour properties, dough rheology, pasting, and fermentation parameters, as well as the bread properties, significantly differed among the studied genotypes. Cappelli produced the bread with the best quality, i.e., the highest volume and lowest firmness. Despite having the same pedigrees, Giovanni Paolo and Padre Pio resulted in significantly different technological properties. Giovanni Paolo flour showed the highest protein content and provided a dough with a high gas production capacity, resulting in the bread having a similar firmness to Cappelli. Padre Pio flour provided bread having a similar volume to Cappelli but a high firmness similar to Khorasan and Garfagnana. The einkorn genotypes, Monlis and Norberto, showed poor fermentation properties and high gelatinization viscosity that resulted in bread with poor quality. Alternatively, they could be more suitable for making non-fermented flatbreads. Our results showed that the improved wheat showed a high versatility of features, which offers bakers a flexible material to make a genotype of bread types.

Research on the Potential Use of Grape Seed Flour in the Bakery Industry

Grape seeds are one of the most accessible by-products of the wine industry in large quantities (about 2.4 million t/year). Numerous researchers have shown that grape seeds have a high potential for use as a functional ingredient in the food industry due to their high content of protein, fiber, minerals, and polyphenols. The aim of the paper is to evaluate the possibilities of using grape seed flour (GSF) in the bakery industry from both chemical and rheological points of view. Research shows that grape seed flour contains about 42 times more fiber than wheat flour and approximately 9 times more calcium, 8 times more magnesium, and 2 times more potassium. To assess this potential, four samples of bread from flour mixtures with 3%, 5%, 7%, and 9% (w/w) degree of replacement with GSF were prepared, analyzed, and compared with a control sample from 100% wheat flour. From a rheological point of view, the baking qualities deteriorate: the water absorption capacity (CH) decreases from 58.2% to 55.8%, the dough stability increases from 8.50 min to 9.83 min, the α slope varies from −0.066 Nm/min to −0.104 Nm/min, the β slope increases from 0.576 Nm/min to 0.630 Nm/min, and the γ slope varies from −0.100 Nm/min to −0.198 Nm/min. The sensory analyses performed by the panel of evaluators enclosed the sensorial characteristics of the samples with 3% and 5% GSF between the two control samples made from flour types 480 and 1250. The conclusions show that the sample containing 7% and 9% are unsatisfactory from rheological and sensorial points of view and the samples with 3% and 5% can be considered a fiber source and a Cu source, respectively, and are rich in Zn.