Anti-staling and quality characteristics of Korean rice cake affected by mulberry (Morus alba L.) leaf powder fortification

Property and quality of japonica rice cake prepared with Polygonatum cyrtonema powder

Rice cake is a common traditional food in China. In this study, the effect of Polygonatum cyrtonema (PC) on the qualities and characteristics of rice cake was investigated. The incorporation of PC powder in rice cakes endowed a light-yellow color and increased the water content and water absorption of products. Rheological analysis showed that the rice cake containing PC exhibited weak-gel properties. Additionally, PC (40%) inhibited the rice cake aging and lowered the hardness of rice cakes to 13.86 N after 4 h storage. In vitro starch digestion analysis showed that PC (40%) reduced the digestibility of rice cakes by decreasing the starch hydrolysis rate from 88.70 to 58.95%, displaying a low estimated glycemic index (eGI) of 52.14. The findings mentioned above indicated that the inclusion of PC powder in rice cakes enhanced their characteristics and attributes, which also provided an approach for the development of PC products.

Storage impact on egg white powder's physical and functional properties

BACKGROUND

Changes in storage temperature and time alter the functional properties of egg white powder (EWP) and determine its quality and shelf-life, finally affecting the consumer acceptance of the products made from EWP. In the present study, the EWP samples were stored at four different temperatures (-20, 4, 25 and 37 °C) for 60 days, and then the protein structural, physical and functional properties of EWP were measured and assessed further for correlation with storage conditions using heatmap.

RESULTS

The viscosity of the EWP solution increased after 30 days. Foaming ability and rheological properties increased first and then decreased compared to untreated samples with the prolonged storage time. Correlation analysis results indicated that the gel hardness, water holding capacity, foaming ability, emulsifying ability, particle size, dispersibility and viscosity of EWP were significantly related to storage time (P < 0.05). Only the gelation properties of EWP stored at 37 °C for 60 days changed significantly and were negatively related to its moisture content (P < 0.05). Additionally, the random coil content of EWP was positively correlated with particle size, moisture content, solubility and gel properties, whereas β-sheet was negatively correlated with them.

CONCLUSION

Compared to other temperatures, the functional properties of EWP were relatively stable under 4 °C. Therefore, the low temperature (4 °C) was selected as the most suitable storage temperature for EWP. The results of the present study could provide a theoretical basis for the shelf-life extension of EWP. © 2022 Society of Chemical Industry.

Development of fermented rice cake containing strawberry showing anti-inflammatory effect on LPS-stimulated macrophages and paw edema induced mice

Strawberry (Fragaria ananassa) is one of the richest sources containing a wide variety of nutritive compounds. Anti-inflammatory activities of fermented rice cake made of strawberry powder as well as rice powder were evaluated. The fermented rice cake containing strawberry powder (SRC) significantly and dose-dependently inhibited NO production in LPS-stimulated RAW264.7 cells without cytotoxicity. Also, SRC effectively suppressed inflammatory gene expression, including iNOS, COX-2, IL-1β, IL-6, and TNF-α. In addition, the production of PGE2, IL-1β, IL-6, and TNF-α was significantly reduced. Furthermore, the anti-inflammatory effect of SRC was investigated using carrageenan-induced paw edema of ICR mice. It was demonstrated that pre-orally administration of SRC at a dose of 50 and 100 mg/kg BW significantly inhibited paw edema induced by carrageenan. This study suggested that the anti-inflammation activities of strawberry rice cake give the potential for increasing the commercialization of rice cake and rice products.

The particle size of rice flour greatly affects the structural, textural and masticatory properties of steamed rice cake (Baekseolgi)

In this study, steamed rice cakes prepared with different particle sized flour were used to investigate how the structures of rice cakes affected masticatory properties and bolus starch hydrolysis. Decreasing the particle size increased the surface areas requiring hydration, resulting in a loose structure and fluffy starch network during gelatinization. Increasing the particle size led to a tight and firm network, but was easily melted in the oral cavity. The chewing cycle and time differed among the samples. The conditions of inter-individual salivary flow rate and salivary α-amylase were diverse. The oral carbohydrate hydrolysis in the bolus before swallowing showed no significant differences in reducing sugar levels among particle sizes. However, salivary concentration was related to initial starch hydrolysis in the oral cavity, indicating the food structures affected mastication factors and physiological conditions. This study provides food structure and physiological factor information that could help design customized foods in industry.

Component changes of mulberry leaf tea processed with honey and its application to in vitro and in vivo models of diabetes

Honey is a traditional food additive that can be used to preserve food, increase the flavour of food, and enhance the effect of some functional foods. Mulberry leaf is a popular tea, and it is also an anti-diabetic medicinal material. In the traditional processing of mulberry leaf tea, honey is a commonly used additive. This study used ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to measure the changes in the contents of 11 components of mulberry leaves before and after processing using honey as an additive. We analysed the absorption and elimination characteristics of mulberry leaves before and after processing in diabetes in vivo models, and then compared the effect of mulberry leaves before and after processing in resisting hyperglycaemia and hyperlipidaemia damage in in vitro models. The results showed that honey, as an additive, not only improves the dissolution of mulberry leaves, but in diabetes models also increases the utilisation of some components. In an in vitro model, honey mulberry leaves could significantly reduce the apoptosis of vascular endothelial cells. This demonstrated that the traditional processing method using honey as an additive could promote the anti-diabetic effect of mulberry tea. So far, this is the first research report on the quality and role of honey as an additive in mulberry leaf processing.Abbreviations: ML: mulberry leaves; HML: honey mulberry leaves; QC: quality control; HQC: high quality control sample; LLOQ: lower limit of quantification; LQC: low-quality control sample; MQC: medium-quality control sample; MRM: multiple reaction monitoring; STZ: streptozotocin.