This study evaluated the Protaetia brevitarsis larvae powder’s characteristic changes using hot air drying (60±2.5oC, 12 h) with different pre-treatment methods, including two sacrifice methods, two storage temperatures, and two defatting processes. Appearance, yield, moisture contents, pH, color, proximate analysis, volatile basic nitrogen level, DPPH radical scavenging activity, and total phenol content were assessed. Results revealed that a combination of blanching, defatting, and -20oC storage temperature resulted in higher total phenol contents, lower water contents, and lower volatile basic nitrogen levels than other methods. Defatted treatment resulted in a higher L-value than the non-defatted treatment. Taken together, these results indicate that a combination of -20oC storage, blanching, and defatting is the optimal pre-treatment method for obtaining P. brevitarsis larvae powder with high total phenol content, low water content, and low volatile basic nitrogen, taking into account cost efficiency considerations.
To develop quality-improved muffins, the influence of the partial replacement of wheat flour with lemon balm powder (LBP) on their quality characteristics was analyzed. Studies were carried out to examine the supplementation of different percentages of LBP (2%, 4%, 6%, and 8%) on the quality characteristics of LBP muffins. The incorporation of LBP significantly affected the physicochemical parameters of muffins. Such incorporation at different levels significantly decreased pH, moisture content, baking loss, hardness, and color parameters, including L*, a*, and b* values of muffins (p<0.05). No significant effect of LBP substitution was found in height changes (p>0.05). Finally, the consumer acceptance test indicated that the highest levels of LBP incorporation (i.e., 8%) had a considerably adverse effect on consumer preferences in all attributes. In contrast, muffins with moderate levels of LBP (4%) showed a good and satisfactory sensorial acceptance in general. Thus, LBP was successfully employed in muffins, improving quality and broadening its potential applications in other bakery products.
Natural environmental resources are considered a prospective source of microorganisms capable of producing biocatalysts with great potential in industrial areas. Arable soil fertilized with peat moss is a habitat for various microorganisms. The present research focused on the isolation and identification of hydrolase-producing bacteria that thrive at a broad temperature range. In this study, a total of 33 strains were isolated from arable soil fertilized with peat moss (Silla Garden in Busan, South Korea). The isolated bacteria were mesophiles and thermophiles with a wide temperature range. Taxonomic identification showed that the isolated strains belonged to 2 phyla, 5 families, 10 genera, and 24 species. Subsequently, the isolated strains were screened for hydrolase (amylase, lipase, and protease) activity. All isolates possessed activity of at least one enzyme and six bacterial isolates produced combined extracellular enzymes. Diversity of soil bacteria species in the present study suggest the potential of soil bacteria in the various industrial applications.
This study was performed to evaluate the quality characteristics and antioxidant activity of Nurungji by varying the purple sweet potato powder addition time (AR: added after rice cooking, BR: added before rice cooking) and powder ratio (0, 2, 4, 6, 8%) on the prepared rice during Nurungji’s manufacturing. In both AR and BR samples, water binding capacity, soluble solid content, reducing sugar, and hardness increased with an increasing proportion of purple sweet potato powder; however, the pH and moisture content decreased. The L value and b value decreased and increased with the influence of anthocyanin in purple sweet potato powder. The total polyphenol, flavonoid, anthocyanin contents, DPPH, and ABTS radical scavenging activity were highest in Nurungji with 8% of purple sweet potato powder. Moreover, AR samples showed higher antioxidant activity than BR samples. Based on the study results above, the preparation of Nurungji with 8% purple sweet potato powder by AR process was more favorable based on the content of antioxidants and antioxidant activity.
This study investigated optimal extraction conditions for applying Capsicum annuum L. leaf as a functional food resource. Capsicum annuum L. leaf was extracted at different extraction solvents (water and 95% ethanol), extraction temperatures (80oC and 100oC), and e xtraction times ( 30, 60, and 9 0 min), a nd t he extracts were e valuated for extraction yield, luteolin content as a major flavonoid component, antioxidant activity, and α-glucosidase inhibitory activity. The extraction yield, luteolin content, DPPH and ABTS radical scavenging activities, and α-glucosidase inhibitory activity of the hot water extract were higher than those of the ethanol extract. In evaluating the extraction temperature of Capsicum annuum L. leaf, the antioxidant activities were similar, but the extraction yields, luteolin contents, and α-glucosidase inhibitory activities were higher at 100oC extraction. In evaluating the extraction time of Capsicum annuum L. leaf, extraction yield increased as the extraction time increased, but antioxidant activity and α-glucosidase inhibitory activity were the highest at 60 min of extraction. These results suggest that the optimum extraction conditions of Capsicum annuum L. leaf are hot water for 60 min at 100oC, and the extracts can be used as a functional food resource.
As coffee consumption increases, coffee extraction's by-products increase. Research on coffee by-product recycling is fundamental as social costs and environmental problems arise from the course of coffee processing, estimated to be 270,000 tons per year. This study attempted to confirm the possibility of an eco-friendly food packaging material by solvating cellulose from spent coffee grounds. For cellulose solubility, delignification and TEMPO (2,2,6,6- tetramethylpiperidin-1-oxyl) oxidation treatment were performed. An optimal plasticizer (glycerol) and a crosslinking agent (cinnamaldehyde) were added to the film-forming solution for film manufacturing, while physical treatment (high-pressure treatment, 276 MPa, 10 times) was done to improve physical properties. Then, the film was dried by a solution-casting method. Physical properties of food packaging materials such as tensile strength, elongation, water-solubility, thickness, and chromaticity were measured. In particular, the film to which 1.5% glycerol was added showed the highest value among the physical properties of the dried film. These results indicate that TEMPOSCG films have potential as eco-friendly food packaging materials in the food industry.
The objectives of this study are to increase the contents of functional compounds and antioxidant activity obtained from ginger (Zingiber officinale Roscoe) extracts using fermentation and enzyme. The optimal conditions (1%, Aspergillus luchuensis) for extraction methods were determined through fermentation treatment of ginger (concentrations of 0.5 and 1%; Aspergillus oryzae and Aspergillus luchuensis). The quality characteristics of the ginger extract for each treatment method (HW, hot water treated; EZ, enzyme; AL, fermentation; ALEZ, fermentation and enzyme) were observed using the optimal conditions. The water-soluble index (WSI) and total sugar content of the ALEZ increased by 2.6 times and 6.5 times, respectively, compared with that of the HW. However, the sum of gingerol and shogaol contents of ALEZ were 73.9% in ratio compared with lower than that of the HW. Antioxidant contents were generally higher in ALEZ, similar to the WSI trend. Therefore, ALEZ was more effective in enhancing antioxidant activity than EZ and AL. The fermentation and enzymatic approach described in this study would be beneficial to food industries for developing ginger functional products and materials.