Effects of the Carbohydrate Sources Nectar, Sucrose and Invert Sugar on Antibacterial Activity of Honey and Bee-Processed Syrups

Honey is a functional food with health-promoting properties. Some types of honey are used in wound care for the treatment of acute and chronic infected wounds. Increased interest in using honey as a functional food and as a base for wound care products causes limited availability of raw honey. Numerous studies suggest that the protein content of honey is mainly comprised of bee-derived proteins and peptides, with a pronounced antibacterial effect. Therefore, the aim of our study was to characterize for the first time the antibacterial activity of raw honeys and bee-processed syrups which were made by processing sucrose solution or invert sugar syrup in bee colonies under field conditions. Furthermore, we compared the contents of glucose oxidase (GOX) and the levels of hydrogen peroxide (H2O2) in honey samples and bee-processed syrups. These parameters were also compared between the processed sucrose solution and the processed invert sugar syrup. Our results clearly show that natural honey samples possess significantly higher antibacterial activity compared to bee-processed syrups. However, no differences in GOX contents and accumulated levels of H2O2 were found between honeys and bee-processed syrups. Comparison of the same parameters between bee-processed feeds based on the two artificial carbohydrate sources revealed no differences in all measured parameters, except for the content of GOX. The amount of GOX was significantly higher in bee-processed sucrose solutions, suggesting that processor bees can secrete a higher portion of carbohydrate metabolism enzymes. Determination of honey color intensity showed that in bee colonies, bee-processed syrups were partially mixed with natural honey. Further research is needed to identify the key botanical compounds in honey responsible for the increased antibacterial potential of honey.

Gummy candies production with natural sugar source: Effect of molasses types and gelatin ratios

Nowadays, attention has been dedicated towards the development of foodstuffs whose constituents are from natural sources. In this study, grape, mulberry, and carob molasses containing natural sugars were evaluated in order to replace the use of sugar syrup and artificial additives in the production of gummy candy which was prepared by varied gelatin ratios. The molasses which have similar °Brix values (78–79) presented different types and amounts of sugar components. High invert sugar with low sucrose was observed in grape and mulberry but high sucrose with low fructose and glucose appeared in carob molasses. Unlike grape and mulberry, carob based jellies had a whitish appearance possibly as a result of the crystallization due to its high sucrose/invert sugar ratio. For all parameters of TPA, carob candy with 5 g/100 g gelatin and grape candy with 10 g/100g gelatin had the lowest and highest values, respectively. Gelatin concentration dependency trend of hardness, gumminess, chewiness and resilience was determined as grape > mulberry > carob. No significant effect ( p > 0.05) on gelling temperatures (21–29 °C) but significant effect (p < 0.05) on melting points (33–39 °C) of molasses types were observed for candies. The properties of grape based candy having higher thermal stability and lower temperature sensitivity were attributed to its higher total sugar contents than other samples. The sensorial acceptability score for molasses gummy candies obtained more than 3.0 on a 5-point hedonic scale. These results illustrate the potential for the use of molasses in a healthier confectionery product development instead of commonly used sugars.

Processing deteriorated beet. Part 1: Indicative and quantitative analysis of the degree of deterioration

For purpose of process control and measures to handle deteriorated beet material it is of the utmost importance to monitor the beet quality parameters indicating beet deterioration. This paper presents an overview of the most appropriate methods to be applied: visual inspection of beet material, analysis of marker components like mannitol and invert sugar, and the analysis of dextran. Critical levels of these components in sugar beet are mentioned, beyond which actions in process operation should be undertaken. Recognizing deteriorating beet quality at an early stage is possible by attention to sudden or gradual changes of particular process parameters and performance indicators, which will be briefly explained.

Integrative transcriptomics reveals genotypic impact on sugar beet storability

Key message An integrative comparative transcriptomic approach on six sugar beet varieties showing different amount of sucrose loss during storage revealed genotype-specific main driver genes and pathways characterizing storability. Abstract Sugar beet is next to sugar cane one of the most important sugar crops accounting for about 15% of the sucrose produced worldwide. Since its processing is increasingly centralized, storage of beet roots over an extended time has become necessary. Sucrose loss during storage is a major concern for the sugar industry because the accumulation of invert sugar and byproducts severely affect sucrose manufacturing. This loss is mainly due to ongoing respiration, but changes in cell wall composition and pathogen infestation also contribute. While some varieties can cope better during storage, the underlying molecular mechanisms are currently undiscovered. We applied integrative transcriptomics on six varieties exhibiting different levels of sucrose loss during storage. Already prior to storage, well storable varieties were characterized by a higher number of parenchyma cells, a smaller cell area, and a thinner periderm. Supporting these findings, transcriptomics identified changes in genes involved in cell wall modifications. After 13 weeks of storage, over 900 differentially expressed genes were detected between well and badly storable varieties, mainly in the category of defense response but also in carbohydrate metabolism and the phenylpropanoid pathway. These findings were confirmed by gene co-expression network analysis where hub genes were identified as main drivers of invert sugar accumulation and sucrose loss. Our data provide insight into transcriptional changes in sugar beet roots during storage resulting in the characterization of key pathways and hub genes that might be further used as markers to improve pathogen resistance and storage properties.