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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.

Rice husk, which contains hemicellulose, can be used as a renewable resource to produce xylooligosaccharide (XOS). However, it is difficult to destroy the lignin structure of rice husk. Steam explosion (SE) is an effective method in destroying the lignin structure to enhance the release of hemicellulose and cellulose. In this study, SE pretreatment was used at different high pressures. The results showed that the lignin structure of rice husk could be collapsed by SE pretreatment, and the chemical structures of rice husk were evaluated by Fourier transform infrared spectroscopy (FTIR). The SE pretreatment resulted in the significant increase of XOS content and antioxidant activities. In summary, SE pretreatment under 2.5 MPa was chosen as a good option for the production of XOS from rice husk.

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.

In this study, we analyzed the potential of using dry matter content for determining ethanol yield of sweet potatoes as one of the raw materials for bioethanol production. We tested dry matter content, total starch content, crude protein content, glucose content, fructose content, sucrose content and fermentation indicators of 29 sweet potato varieties in Henan province. Correlation analysis between main component contents of sweet potato and the fermentation indicators were carried on. The results showed that there was strong linear correlation between dry matter content and bioethanol yield (R2 = 0.935). In order to prove the conclusion, we also tested dry matter content and ethanol yield of another 24 sweet potato varieties. Based on the dry matter content and linear correlations, we predicted the ethanol yields. We performed correlation analysis between the predicted values and the measured values of bioethanol yield of the 24 sweet potato varieties, and found highly significant positive correlation between the predicted values and the measured values. These results confirmed the reliability of using dry matter content for bioethanol production prediction for sweet potatoes.

To meet the demands for screening out the optimal utilization channel for biomass from wheat straw, a number of researches have been reported in the comprehensive utilization about wheat straw including cellulose, hemicellulose and lignin. By reviewing the research status, processing method and comprehensive application of wheat straw, this paper summarizes the application fields, main pretreatment processing methods and bio-products of wheat straw. The paper also detailed novel pretreatment methods and bio-products during the comprehensive utilization of wheat straw. The assessment of more effective pretreatment methods has enabled the examination of wheat straw materials’ potential in the field of lignocellulose that, today, is little exploited. Bioconversion of lignocellulose to bioproducts e.g. bioethanol, biohydrogen and bio-composites has made achievements, however, several limitations such as pretreatment methods remain to be solved.

To meet the demands for screening sweet potato tubers for bioethanol production, 12 genotypes of sweet potato tubers were collected from Henan, Shandong, Anhui, and Jiangsu Provinces, China. Based on the optimized determination method of the percent dry content, the nutritional composition and fermentation properties were studied. There were differences in the compositions and their correlations among the sweet potato varieties. The results showed that the starch content was weakly correlated with other ingredients, while the percent dry content and fermentable sugars contents had a close correlation with starch content. The percent dry content significantly and positively correlated with the flour and fermentable sugars contents. The percent dry content and starch contents had a significantly positive correlation, with a correlation coefficient that reached 0.96.

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.

As a highly valued fungus, Cordyceps militaris has been widely used all over the world. Although the wild resources of C. militaris are limited, the fruiting bodies of C. militaris have been successfully cultivated on a large-scale. However, the high-frequency degeneration of C. militaris during subculture and preservation seriously limits the development of the C. militaris industry. How to solve the degeneration of C. militaris has become an unsolved bottleneck problem throughout the whole Cordyceps industry. The aim of this review is to illustrate the phenotypic changes after the degeneration of C. militaris, focusing on the causes (including environmental factors and genetic variation) of C. militaris degeneration. Moreover, genetic variation is the root cause of the degeneration of C. militaris strains. Measures to prevent the degeneration of C. militaris are also discussed in this review. This paper will increase understanding of the degeneration mechanism of C. militaris, provide a reference for solving the degeneration problem of C. militaris, and lay a foundation for promoting the sustainable development of C. militaris.

Resistant starch (RS) modified by L-malic acid is a prebiotic that passes intact through the stomach and small intestine, and the optimum conditions determined using a response surface methodology (RSM) based on a Box–Behnken design (BBD) were: reaction temperature, 146 °C; pH, 1.46; reaction time, 5.52 h; and mass ratio (M : S), 0.60. After cooking at 100 °C, RS treated with L-malic acid contained substantial amounts of RS and slowly digestible starch (SDS) fractions (74.6%), although the rapid digestible starch (RDS) fraction still remained at about 25.4%. It was presumed that the decrease in the SDS content of the malate starch production treated by L-malic acid was because of the presence of RS or SDS type fractions formed by an amylose–malate complex substance and branch–branch or branch–linear interactions. The Fourier-transform infrared spectroscopy results showed that L-malic acid treated corn starch showed a novel band at 1732 cm−1, which was an indication of CO stretching because of the corn starch linked with maleic anhydride.

With layered milling flour technology, the efficiency of the nutrient distribution and hardness was demonstrated with the green and normal wheat separation milling. The results showed that the total content of amino acid in green wheat was 8.3%–13.0% higher compared to the common wheat. Comparing the main nutriments Se, Fe, and Ca between green wheat and common wheat, the results showed that different milling treatment methods 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 green and normal wheat products and also for its processing and utilization.

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.

There is a growing concern about the serious harm of radioactive materials, which are widely used in energy production, scientific research, medicine, industry and other areas. In recent years, owing to the great side effects of anti-radiation drugs, research on the radiation protectants has gradually expanded from the previous chemicals to the use of natural anti-radiation drugs and functional foods. Some reports have confirmed that anthocyanins are good antioxidants, which can effectively eliminate free radicals, but studies on the immunoregulatory and anti-radiation effects of anthocyanins from lingonberry (ALB) are less reported. In this experiment, mice were given orally once daily for 14 consecutive days before exposure to 6 Gy of gamma-radiation and were sacrificed on the 7th day post-irradiation. The results showed that the selected dose of extract did not lead to acute toxicity in mice; while groups given anthocyanins orally were significantly better than radiation control group according to blood analysis; pretreatment of anthocyanins significantly (p < 0.05) enhanced the thymus and spleen indices and spleen cell survival compared to the irradiation control group. Pretreatment with anthocyanins before irradiation significantly reduced the numbers of micronuclei (MN) in bone marrow polychromatic erythrocytes (PCEs). These findings indicate that anthocyanins have immunostimulatory potential against immunosuppression induced by the radiation.

To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO(2) laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO(2) laser irradiation. The present work demonstrated that the CO(2) laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO(2) laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO(2) laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.