Search Results (3)

Climate change significantly affects honey bee populations and their access to natural food sources, demanding alternative economic feed sources. Longan stands out as the most important fruit crop in Southeast Asia, but with a surplus of low-grade fruit that is not suitable for the market. This study investigates the potential of longan syrup as an alternative carbohydrate source for honey bees by measuring sugar composition, phytochemical profiles, feed, and survival, as well as the resulting gut microbial changes. Processed longan syrup contains 8.2, 85.1, and 33.1 mg/g of sucrose, glucose, and fructose. Total phenolic and flavonoid contents were 24.94 and 129.78 mg/g, respectively, showing a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical inhibition rate of 26.78% and an 87.82% antiradical activity rate via 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). In vitro supplementation studies indicated that survival was highest in the 50% w/v sucrose syrup condition (control), followed by honey bees fed with 10%, 20%, and 30% longan syrup concentrations, respectively. Analyses of honey bee gut microbiomes revealed that longan syrup supplementation increased fermentative microorganisms such as Lactobacillus and Fructobacillus, which are beneficial for honey bees’ health. Even though the addition of higher amounts of longan syrup would not be recommended, a 10% addition would be beneficial to honey bees’ health through the modulation of gut microbiomes, demonstrating its potential as a dietary supplement that is a cost-effective and sustainable alternative to sugar syrup during shortages of natural carbohydrate sources. Full article

The increase in honey fraud in the global market has highlighted the importance of pollen analysis in determining or confirming the botanical and geographical origins of honey. Numerous studies are currently underway to develop efficient and rapid methods for the determination of the quality, botanical, and geographical origin of honey. Typically, the physicochemical analysis of honey is used to evaluate its quality and geographical source. In this study, flow cytometry, a technique extensively employed in immunology and hematology, was first applied to analyze and characterize pollen from longan honeys from Taiwan and Thailand. The flow cytometry was employed for forward scatter (FSC), side scatter (SSC), Y610-A, and NUV450 to analyze longan honey samples from Taiwan and Thailand. Taiwan’s longan honeys were rich in pollens; however, based upon the FSC and SSC analyses, the pollens from Thai longan honeys were larger and more granular. The Y610/20 emission area was greatest in Thai pollens. The NUV450 measured in the near UV laser was also greater in Thai pollen. Additionally, honey samples were also analysed for physiochemical properties including moisture content, pH, ash content, viscosity, and hydroxymethylfurfural (HMF) for physiochemical properties of longan honey samples from both countries. The moisture content of honey from Taiwan varied between 20.90% and 23.40%, whereas honey from Thailand ranged from 19.50% to 23.50%. A total of 60% of Taiwan’s longan honey was found to have a dark amber color, and only 20% of Thai longan honey exhibited a dark amber color. Furthermore, the pH range of honey from Taiwan was found to be between 4.00 and 4.16, and the pH of Thai honey ranged from 4.01 to 4.12. The ash content of honey samples from Taiwan ranged from 0.05% to 0.23%, and Thai honey had a range of 0.01% to 0.9%. All samples were negative for the Fiehe’s test, indicating the absence of HMF. This analysis lays the groundwork for rapid identification the origins of the honey, applying flow cytometry in conjunction with physicochemical analysis to assess its quality. Full article

The activities of enzymes are the basis of evaluating the quality of honey. Beekeepers usually use concentrators to process natural honey into concentrated honey by concentrating it under high temperatures. Active enzymes are very sensitive to high temperatures and will lose their activity when they exceed a certain temperature. The objective of this work is to study the kinetic mechanism of the temperature effect on diastase activity and to develop a nondestructive approach for quick determination of the diastase activity of honey through a heating process based on visible and near-infrared (Vis/NIR) spectroscopy. A total of 110 samples, including three species of botanical origin, were used for this study. To explore the kinetic mechanism of diastase activity under high temperatures, the honey of three kinds of botanical origins were processed with thermal treatment to obtain a variety of diastase activity. Diastase activity represented with diastase number (DN) was measured according to the national standard method. The results showed that the diastase activity decreased with the increase of temperature and heating time, and the sensitivity of acacia and longan to temperature was higher than linen. The optimum temperature for production and processing is 60 °C. Unsupervised clustering analysis was adopted to detect spectral characteristics of these honeys, indicating that different botanical origins of honeys can be distinguished in principal component spaces. Partial least squares (PLS) and least squares-support vector machine (LS-SVM) algorithms were applied to develop quantitative relationships between Vis/NIR spectroscopy and diastase activity. The best result was obtained through Gaussian filter smoothing-standard normal variate (GF-SNV) pretreatment and the LS-SVM model, known as GF-SNV-LS-SVM, with a determination coefficient (R²) of prediction of 0.8872, and root mean square error (RMSE) of prediction of 0.2129. The overall results of this paper showed that the diastase activity of honey can be determined quickly and non-destructively with Vis/NIR spectral methods, which can be used to detect DN in the process of honey production and processing, and to maximize the nutrient content of honey. Full article