Rapid Detection of Thermal Treatment of Honey by Chemometrics-Assisted FTIR Spectroscopy

Honey, as a nutritious natural sweetener produced by honeybees, offers a unique biochemical composition with great benefit to human health. Transportation and storage conditions as well as violations of processing can lead to decomposition of vitamins, destruction of the integrity of the antioxidant components and enzymes, and further biochemical changes with impact on nutritional quality. We developed a fast detection method of adulterations or changes of honey caused by thermal exposure, which does not require any sample pretreatment. By Fourier-transform infrared spectroscopy, supported by chemometrics methods, we investigated three types of raw honey before and after heat treatment for varying exposure times at different temperatures. Applying principal component analysis and linear discriminant analysis to the preprocessed spectroscopic data, allowed us to discriminate raw honey from thermally altered ones even at low temperatures of 40 °C with high accuracies ≥ 90%.

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.

Biochemical content, minerals, and antioxidant activity of fruit jiaosu obtained by natural fermentation

This study was conducted to determine the pH, protein concentration, mineral, phenolic, flavonoid, and organic acid contents, as well as the antioxidant activity of three batches of fruit jiaosu (F1B3, F1B4, and F1B5). The jiaosu was prepared by mixing ten types of fresh fruits, raw honey, and water (3:1:10, w/w/w), and fermented at room temperature for six months. All fruit jiaosu had low pH (2.96–3.69), and the protein concentration was ranged from 8.45 to 16.2 µg/mL. Potassium (605.0–657.2 mg/L) was found to be the most abundant mineral in all the samples, followed by magnesium, calcium, and sodium. The total phenolic and flavonoid contents were 183.1–210.5 µg gallic acid equivalent/mL and 45.2–53.8 µg quercetin equivalent/mL, respectively. Acetic acid was the major organic acid in the F1B4 and F1B5 samples (6.58 g/L and 20.7 g/L, respectively) while the F1B3 sample contained the highest amount of lactic acid (12.1 g/L). Ascorbic and citric acids were present in small amounts in all samples. All the samples showed stronger scavenging activity against 2,2-diphenyl-1-picrylhydrazyl radicals (half-maximum inhibitory concentration, IC50: 13.6–16.8% v/v) than against hydrogen peroxide (IC50: 47.2–50.6% v/ v). The ferric reducing antioxidant power and oxygen radical absorbance capacity values for the samples were 14.9–20.9 µg ascorbic acid equivalent/mL and 23.9–25.4 mg Trolox equivalent/mL, respectively. The results indicated that the fruit jiaosu is a complex acidic solution containing proteins, minerals, phenolic compounds, and organic acids with antioxidant activities. Natural fermentation may cause variations in the organic acid content of the fruit jiaosu.

Screening of Some Romanian Raw Honeys and Their Probiotic Potential Evaluation

This study aimed to characterize raw honeys from different geographical origins in Romania, in respect of chemical composition, microbiological examination and evaluate their probiotic potential. The physico-chemical determinations were performed in APHIS-DIA Laboratory, Cluj-Napoca, Romania, using standard validated methods. Bacterial identification was performed for each sample and each colony type using Vitek® 2 Compact 15 system and PCR amplification using 16S rDNA bacterial universal primers (27F, 1492R), species being confirm by sequences analysis. In five raw honey samples, we have identified probiotic bacteria, such as: Bacillus mycoides, Bacillus thuringiensis, Bacillus amyloliquefaciens, Bacillus subtilis, and Bacillus velezensis. Generally, all honey samples meet the standard values for chemical composition. However, one sample having 7.44% sucrose was found to have also probiotics bacteria from the genus Bacillus because sucrose is a substrate for probiotics development. In conclusion, the Romanian raw honey can be a potential reservoir of probiotics, which confer a health benefit for consumers.

Evaluation of sex steroid hormones and reproductive irregularities in diethyl phthalate exposed premature mice: modulatory effect of raw honey against potential anomalies

Phthalates, plasticizing chemicals are top-rated environmental contaminants. Diethyl phthalate (DEP), a chief member of this family was declared a potent endocrine-disruptor and carcinogen in animals and humans. The current study was designed to explore the probable reproductive damage induced by DEP and the therapeutic efficacy of raw honey in male albino mice. Four weeks old 50 male mice, were randomized equally in five groups, as control (C) received 0.1 ml distilled water; vehicle control (VC) received 0.1 ml corn oil; DEP (3mg/g/BW) dissolved in corn oil; Honey control (HC) administered 0.2 mg/g/day); P + H administered with DEP and honey (3mg and 0.2 mg/g/BW/day respectively). Mice were treated through oral gavage for 54 days routinely, acclimatized for 6 days and dissected. In the first instance, the antioxidant potential and total phenolic contents of honey were analyzed through Ferric reducing antioxidant power assay and Folin-Ciocalteu assay to confirm the antioxidant capacity of honey. The morphological, morphometric, histological, micrometric, sperm count, hormonal analyses, and antioxidant capacity test in tissue homogenates were conducted by using tissues (testis, epididymis) and blood samples of mice. Mice exposed to DEP have a significant increase in body weight, LH level, seminiferous tubule lumen diameter and decrease in the gonado-somatic index, testosterone level, sperm count, and seminiferous tubule diameter. Additionally, histopathology of testes showed interstitial spaces dilations, exfoliations, Leydig cells atrophy, germ cell degenerations and spermatid retention in DEP exposed testes sections. However, concomitant use of honey and DEP had shown a significant improvement in histopathological lesions, steroid hormone levels, and healthy sperm count. By these results, it is concluded that honey possessed antioxidant potential that can efficiently protect DEP-induced anomalies in male mice.

Quality Assessment of Raw Honey Issued from Eastern Romania

Romania is known among the main European honey producers, due to the variety of landforms as well as the diversity of the flora. Thirty-four honey samples of the acacia, linden and multifloral types, produced in eastern Romania and collected during 2013–2018, were physico-chemically analyzed using methods provided by the national and EU standards. The results of water-insoluble solids, color and refractive index were found to be 0.023–0.131%, 0.3–76.4 mm Pfund and 1.485–1.499, respectively. The moisture content ranged between 15.20% and 20.77%, solid substances content ranged between 79.23% and 84.80% and total soluble substances content ranged between 77.83 °Brix and 83.26 °Brix. The obtained values of specific gravity were from 1.414 to 1.450 g/cm3, pH ranged from 3.673 to 5.503 and free acidity ranged between 2.4 meq and 50 meq kg−1. The ash content and the electrical conductivity varied between 0.030 and 0.543% and 130 and 679 µS cm−1, respectively. Pearsonʹs correlation analysis showed an intense association of the ash content with electrical conductivity (r = 0.81). Our findings reveal the qualitative level of Romanian honey and the variation in quality parameters due to factors such as geographical region, climatic conditions, botanical origin and handling or storage conditions.