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Corn is a high starchy cereal crop with the highest production and provides over 85% of the starch produced worldwide. Various by-products, differentiated by technological process features such as steep liquor, corn germ, corn bran, gluten, are created largely during corn starch processing. They are inexpensive, nutrient-rich, and vary widely in chemical composition such as proteins, oils, carbohydrates, and minerals. In an increasingly resource-constrained modern world, the utilization approach of these by-products for non-starch industrial processing is attractive widely considering both nutritive value and economic aspects. In fact, at present, applications of these by-products can often be found in feed, fermentation, nutrient extraction and other industries. For example, protein-rich corn gluten can be used as a good animal feed, and corn germ can be used as a raw material for the high-quality edible oil industry. Undoubtedly, increasing utilization means that these by-products will no longer be treated as waste but will be transformed into high value-added products. In this work, the separation process and chemical composition of several main by-products of the corn starch industry is briefly described, and the application in many industrial fields of these by-products over the last ten years are discussed in particular. This review attempts to summarize all aspects of the application and research of these by-products. For the by-products of the corn starch industry, the most promising way is to be utilized in high value and used to produce high value-added products. According to the characteristics of their chemical composition, they have a better application prospect and research significance in the industries directly related to human beings, such as medicine, green food and health care products. In fact, in recent years, some researchers have recognized this and carried out the research. It is clear from these studies that the main issues to be faced now and in the future are how to produce efficiently while maintaining the quality of the product and using it effectively. The retrospective discussions also provide some ideas for other grain and oilseed crops to be fully utilized.

When harvesting corn, corn silk was discarded as waste, including the compounds isolated and identified from corn silk such as flavonoids, sterols, alkaloids, polysaccharides, organic acids, volatile oils, trace elements, and multivitamins. It not only pollutes the environment but also wastes resources. In this paper, extraction methods commonly used for extracting flavonoids from corn silk were reviewed, such as reagent method, enzymatic method, microwave, supercritical CO2 extraction, ultrasonic, and microwave-assisted ultrasonic. Flavonoids are natural antioxidants and have application value in scavenging free radicals, inhibiting bacteria, and regulating blood lipids. The in vitro biological activities of flavonoids from corn silk extracted by different extraction methods were also compared.

Wheat germ albumin (WGA) is rich in nutrients and contains a number of antioxidant polypeptides. The effects of microwave-assisted alkaline protease, neutral protease, papain and compound protease on the degree of hydrolysis of WGA and the clearance rate of DPPH• were comparatively studied. The results showed that papain had the best proteolytic activity. The functional properties of WGA and its hydrolysis polypeptides were determined. The results showed that the solubility of WGA increased after papain hydrolysis, and the apparent viscosity and foam stability reduced. Compared with the amino acids of WGA, the proportions of proline, histidine, glycine, lysine, and glutamic acid in the enzymatic hydrolysis products increased, while the proportions of leucine, phenylalanine, arginine and isoleucine decreased. After papain hydrolysis, the surface structure was loose, and the surrounding blocks became more rounded.

The objective of this study was to evaluate the effects of different colour-grained wheat flours on protein, TDF, fat, amino acid, microelement, physicochemical index, nutritional quality, farinograph properties and tensile test. The protein content of colour-grained wheat is higher than that of the common wheat, which is 11.74%–18.17 higher than the common wheat. The amount of essential amino acid content was 7.31%–18.13% higher than that of common wheat. By combination technology, No.6 (A2B3C1) showed the greatest tensile test. Changes in qualities resulted from the combination of different flour with granules and gluten. The results of the current study offer opportunities for the steamed bread and noodle industry to use colour-grained wheat flours as an ingredient for enhancing the nutrient value amount of dough.

Cereal products are the most important dietary source for energy intake and several bioactive compounds with high concentrations in the bran and the germ. Different cereal products provide a rich source of bioactive phytochemicals, namely, phenolic acids, carotenoids, tocopherols, alkylresorcinols, benzoxazines, phytosterols, and lignans. The bioactive substance alkylresorcinols (ARs) present in the whole cereal can inhibit enzyme activity, prevent bacterial or fungal infection, reduce cholesterol absorption, prevent cancer, and resist oxidation. In this paper, we discussed the biological activity of ARs in whole cereal products. Understanding the effects of processing on cereal phytochemicals will help us to develop improved processes for processing cereal foods with higher retention rates of bioactive compounds.

Wheat germ, an important by-product in the flour milling industry, is known for its nutritive value. This study investigated the effects of wheat germ supplementation on the quality of steamed bread. Raw wheat germ (RWG) or defatted wheat germ (DWG) was added to wheat flour at compositions of 1–11% (w/w). Results showed that RWG supplementation increased the wet gluten content of dough, but decreased the gluten index of steamed bread compared to the raw flour. However, opposite trends were observed by addition of DWG. Both RWG and DWG had generally similar effects on disulfide bond content. The color test showed that high levels of wheat germ were associated with a decreased L∗ value and an increased b∗ value. The a∗ values stayed close to a light red color irrespective of germ type. Sensory evaluation ratings and textural analysis indicated that steamed bread with acceptable quality attributes can be prepared from wheat flour fortified with wheat germ at less than 3%.

The use of low cost and abundant corn stover in yeast fermentation can reduce product costs. In this study, bioethanol was produced from a hydrolysate of corn stover using immobilized yeast. A kinetic model was established for the total reducing sugar consumption and the production of bioethanol. The parameter estimation for kinetic modeling considered the main process variables during bioethanol production from corn stover. Total reducing sugar concentrations decreased exponentially in the bioethanol fermentation for 6 h; consumption was more than 90%. To use kinetic modelling of yeast growth for bioethanol fermentation, the value of μmax reached 0.2891 h-1, and the matrix inhibition constant (KIS) and production inhibition constant (KIP) were 8.9154 g/dm3 and 0.00676 g/dm3, respectively. To use kinetic modelling of fermentation time on bioethanol, the maximum ratio of bioethanol production rate (qmax) reached 1.427 g/g•L. However, KIS was 2.813 g/dm3, and KIP was 0.0149 g/dm3.

The total phenolic content, total flavonoid content, vitamin C content, and antioxidant activities of ethanol extracts from different kiwifruit varieties (Actinidia kolomikta, Actinidia arguta, Actinidia chinensis) were determined in this study. Multiple scavenging activity assays including the hydroxyl radical, O(2) (-)·radical, DPPH, and the ABTS(+) radical scavenging activity assays were used to identify the antioxidant activities of Actinidia extracts. The cell viability of HepG2 and HT-29 cells was also examined in this study. The results demonstrated that the Actinidia kolomikta extract had a higher antioxidant activity than the other two Actinidia extracts. There is a positive correlation between antioxidant activity and the polyphenols and vitamin C content in all three extracts (R(2) ≥ 0.712, p0.05). The Actinidia arguta extract had the highest inhibitory effect on HepG2 and HT-29 cell growth. These results provide new insight into the health functions of fruit and demonstrate that Actinidia extracts can potentially have health benefits.

With layered milling flour technology, the efficiency of the nutrient distribution and hardness was demonstrated with the purple and normal wheat separation milling. The results showed that the total content on amino acid in purple wheat was 8.2–12.9% higher than the common wheat. Compared with the main nutriments Se, Fe, Ca between purple wheat and common wheat, the results showed that different milling methods treatment are capable of separating the different wheat flour from endosperms, bran, and aleurone layers. Micro and physicochemical characterization of different wheat flour and layers by means of microscopy techniques and images analysis provided relevant qualitative and quantitative information, which can be useful for the study of the microstructure of purple and normal wheat products and also for its processing and utilization. Practical applications Color wheat has gained more importance in the recent years due to its health benefits. Purple wheat is balanced in amino acid, mineral elements, and Wet gluten. Therefore, purple wheat is an excellent flour product source according to the Association of Official Agricultural Chemists (AOAC). Purple wheat rich in amino acid such as leucine, proline, serine, glycine, threonine, and glusate provide important roles in the quality and nutrient value of dough. Lately, the food industry has had a strong interest on purple wheat due to their benefits such as better delivery of protein components, and greater stability and functional performance. Using purple wheat as an ingredient in a flour product will not only improve the nutritional profile of the dough but will also substantially increase the natural microelement content. This study describes the development and characterization of flour product containing purple wheat.

CO2 laser pretreatment to improve the enzymatic hydrolysis of corn stover for production of monosaccharide, was investigated. Response surface methodology (RSM), at a three-variable, three-level experiment Box-Behnken design (BBD) established the following optimum pretreatment parameters: time, 67.53 min; power, 264.33 W; and liquid-to-solid ratio, 21.29:1 (mL/g). Under these conditions, the reducing sugars produced was 4.941 mg/mL for cellulase hydrolysis. This amount matched the predicted value and increased cellulase hydrolysis from 14.47% to 30.84%. Scanning electron microscopy (SEM) showed that CO2 laser pretreatment converted the smooth into a rough and porous surface, which promoted the enzyme access and resulted in a high specific reducing sugars production rate.