To improve the edible quality of reheated pre-cooked flatbreads, an emulsifier-free sample was set as the control. The effects of monoglyceride, soy lecithin, diacetyl tartaric acid esters of mono- and diglycerides (DATEM), sodium stearoyl lactylate (SSL), and calcium stearoyl lactylate (CSL) on the moisture content, texture, water distribution, color, microstructure, Fourier transform infrared (FTIR) spectra, and sensory quality of flatbreads were investigated. The results showed that emulsifier types had significantly effects on the quality of reheated pre-cooked flatbreads. The DATEM group presented the highest moisture content (35.83%), which was significantly higher than that of the control group (31.97%). All emulsifiers significantly reduced the hardness of samples. The SSL group had the lowest hardness and chewiness values, which were 12 547.39 and 5 622.49 g, respectively. The soy lecithin group showed the highest springiness (0.88), and the CSL group had the highest cohesiveness (0.64). The CSL group had the highest L* and b* values of 60.33 and 23.54, respectively, and the SSL and CSL groups obtained higher color sensory scores. Low-field nuclear magnetic resonance results indicated that different emulsifiers changed the water distribution in samples. Scanning electron microscopy observations revealed that DATEM group formed a relatively compact, continuous, and homogeneous matrix structure, while the SSL group presented a relatively open pore structure. The main absorption peak positions of FTIR spectra in all groups were basically consistent, and no distinct new characteristic peaks were observed. It indicated that the effects of emulsifiers were mainly related to the non-covalent interactions and structural rearrangements among water, starch, protein, and lipid in the system. In the sensory evaluation, the SSL group obtained the highest total score (94.64), followed by the DATEM group (93.67). Comprehensive analysis showed that under the experimental conditions of this study, SSL was most conducive to reducing hardness, improving mouthfeel, and enhancing comprehensive sensory quality, while DATEM had more advantages in improving water retention capacity and maintaining matrix continuity.
Convenience staple foods are an important branch of the modern food industry, and the technical level of their processing equipment technology directly determines product quality, safety and production efficiency. Market growth coupled with consumption upgrading has put forward new requirements for flexibility, precision and high efficiency in processing equipment. Focusing on processing equipment for convenience staple foods, this paper systematically sorts out the international technological evolution, domestic development status and policy trends of the industry. Internationally, Japan takes precision control and sterilization as its core competitiveness, Europe and the United States focus on hygienic design, modularization and quick-freezing technologies, and South Korea features market-driven improved innovation. Globally, the industry presents three common characteristics: high-speed production, modular design and digital integration. China's processing equipment has advantages in complete machine integration and large-scale production. Nevertheless, it has shortcomings such as high external dependence on core technologies, insufficient flexibility and intelligence, contradictions between nutritional retention and processing efficiency, pressures of green and low-carbon transition, imperfect standard system and inadequate food safety guarantee, which constitute the bottlenecks restricting industrial development. At the policy level, China is shifting from a scale-oriented development to quality- and intelligence orientation, emphasizing whole industrial chain governance and green and low-carbon development. Looking ahead, the industry will to evolve toward the deep integration of intelligence and digitalization, green and sustainable development, flexibility and modularization, integration of new processing technologies, personalized nutrition customization, and whole industrial chain collaboration and domestic localization. This review intends to provide a reference for relevant research and industrial decision-making.
Convenient staple foods are important product forms for staple food industrialization, central kitchen distribution, cold chain circulation and household convenient consumption. The formation and retention of their quality have become a research hotspot in the field of grain processing in recent years. This paper reviews the research progress of convenient staple food processing, focusing on typical products such as instant rice, rice noodles, fresh wet noodles, frozen dough, and vermicelli. It summarizes the current research status from the perspectives of texture properties, rehydration and reheating performance, cooking quality, storage stability, and edible quality. It outlined the effects of starch composition and fine structure, protein network, lipid migration and complexation, polysaccharide gel formation, salt ion effects, as well as small-molecule sugars and polyols on the structure formation, water distribution, retrogradation and sensory quality of convenient staple foods. It analyzes the effects of different food components on the quality of staple food after processing. It explores the roles of emerging processing technologies such as hot-wet steam treatment, electric field treatment, ultrasound and ultra-high pressure in promoting heat and mass transfer, constructing rehydration channels, regulating gel network structure, improving curing uniformity, inhibiting ice crystal growth and delaying quality deterioration. It further summarizes the effects of raw material components and process parameters on key quality indicators of convenient staple foods, including hardness, elasticity, adhesiveness, broken strip rate, cooking loss rate and rehydration efficiency. This study aims to provide theoretical reference and technical support for the texture regulation, quality improvement, process optimization, and product development of convenient staple foods.
This study systematically evaluated the effects of four freezing methods including refrigerator freezing (RF), liquid-conductive freezing (LCF), liquid nitrogen freezing (LF), and individual quick freezing (IQF) on the quality characteristics of brown rice fried rice during 90 days of frozen storage, by monitoring the changes in pH value, fatty acid value, moisture content and distribution, starch short-range ordering and crystallinity. The results showed that the LF group exhibited the best frozen-storage quality throughout the storage period,, with only a 5.01% decrease in pH value, an increase of 11.41 in fatty acid value from the initial value to day 90, a 4.19% reduction in moisture content throughout the storage period, the lowest total increment of 4.83% for the R1 047/1 022 peak absorbance ratio, and a 62.15% increase in starch crystallinity from 5.31% to 8.61%. The LCF group and IQF group showed similar performance, and the LCF group was slightly better than the IQF group; both were significantly outperforming the RF group. It indicated that LF treatment can significantly inhibit moisture loss and starch retrogradation of fried brown rice during frozen storage. In comparison, although LCF was less effective than LF, it was still superior to the widely applied conventional freezing treatments on the market. This study clarified how rapid freezing affects the frozen-storage characteristics of frozen fried brown rice by influencing moisture state, molecular mobility and other multifaceted factors, which provides a theoretical basis for optimizing the processing technology of frozen rice products and offers a new methodological strategy for the frozen storage of frozen rice products.
To investigate the microscopic modification effects of mechanical comminution pretreatment on the fiber structure of corn stover and improve its the resource utilization potential, natural corn stover was selected in this study. With mechanical comminution applied as the pretreatment method, multiple characterization techniques including X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) were adopted to systematically explore the regulatory effects of mechanical comminution pretreatment on the crystal structure, functional group properties and micromorphology of corn stover fibers. The results demonstrated that mechanical comminution pretreatment could disrupt the crystalline structure of cellulose in corn stover, reduce its crystallinity, and expose more amorphous regions and reactive sites. Meanwhile, the treatment could disintegrate intact long strip fibers into micron scale fragmented particles, strip the surface lignin barrier, generate abundant cracks and rough fracture surfaces, and significantly increase the specific surface area of the raw material.This study elucidates the microscopic impacts of enzymatic hydrolysis and fermentation accessivility through mechanical comminution pretreatment, and provides a theoretical basis for the resource utilization of corn stover in scenarios such as feed quality improvement and bioconversion.
