Stability of volatile compounds of honey during prolonged storage

Dynamic variation in the aroma characteristics of Rhus chinensis honey at different stages after capping

The ripening characteristics after capping of honey are favourable for improving its quality. However, research on the variation and formation of aroma characteristics of honey in this process is lacking. Therefore, the present study was carried out with different stages of Rhus chinensis honeys (RCHs) after capping and identified 192 volatiles with varying levels of concentration. "Fruity" was the main aroma characteristic of RCHs at different stages after capping, mainly contributed by (E)-β-damascenone. Methyl salicylate might be a potential indicator for differentiating RCHs at different stages after capping. The metabolic pathway analyses revealed that the aroma compounds in RCHs undergo transformation at different stages after capping, which subsequently affects its aroma characteristics formation. This work is the first to study the dynamic changes in honey aroma characteristics after capping from multiple perspectives, and the results are of great significance for understanding the aroma characteristics after capping and quality control of honey.

Monitoring Volatile Organic Compounds and Aroma Profile of Robinia pseudoacacia L. Honey at Different Storage Temperatures during Shelf Life

Bee honey has different volatile organic compound profiles that depend on the botanical origin and the state of conservation and which are mainly responsible for its specific aroma. During honey storage, the profile of these molecules and other indicators, such as 5-hydroxymethylfurfural and the diastatic index, can change depending on temperature and time. This study analyzed the variations that these parameters in acacia honey stored at three different temperatures for a total period of 550 days, using gas chromatography coupled with mass spectrometry and an electronic nose equipped with 10 different sensors. The results confirm that the composition of acacia honey varies over time due to both the reduction in the concentration of volatile molecules (e.g., formic acid, a natural acaricide) and the increase in compounds resulting from heat-dependent degradations (e.g., 5-hydroxymethylfurfural). This study supports the usefulness of the electronic nose for the early detection of aromatic alterations in honey subjected to high-temperature storage.

Identification of Volatile Markers during Early Zygosaccharomyces rouxii Contamination in Mature and Immature Jujube Honey

Osmotolerant yeasts are considered one of the major contaminants responsible for spoilage in honey. To address the signature volatile components of jujube honey contaminated by Zygosaccharomyces rouxii, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and chemometrics analyses were used to analyze the variation of volatile substances during early contamination of mature and immature jujube honey. Undecanal, methyl butyrate, methyl 2-nonenoate, methyl hexanoate, and 2-methyl-3-pentanone were identified as signature volatiles of jujube honey contaminated with Z. rouxii. In addition, methyl heptanoate, 2,6,10-trimethyltetradecane, and heptanal were identified as potential volatile signatures for immature jujube honey. The R² and Q² of OPLS-DA analyses ranged from 0.736 to 0.955, and 0.991 to 0.997, which indicates that the constructed model was stable and predictive. This study has demonstrated that HS-SPME-GC-MS could be used to distinguish Z. rouxii-contaminated jujube honey from uncontaminated honey based on variation in VOCs, and could provide theoretical support for the use of HS-SPME-GC-MS for the rapid detection of honey decomposition caused by Z. rouxii, which could improve nutritional quality and reduce economic losses.

In Vivo Anti-Alzheimer and Antioxidant Properties of Avocado (Persea americana Mill.) Honey from Southern Spain

There is growing evidence that Alzheimer's disease (AD) can be prevented by reducing risk factors involved in its pathophysiology. Food-derived bioactive molecules can help in the prevention and reduction of the progression of AD. Honey, a good source of antioxidants and bioactive molecules, has been tied to many health benefits, including those from neurological origin. Monofloral avocado honey (AH) has recently been characterized but its biomedical properties are still unknown. The aim of this study is to further its characterization, focusing on the phenolic profile. Moreover, its antioxidant capacity was assayed both in vitro and in vivo. Finally, a deep analysis on the pathophysiological features of AD such as oxidative stress, amyloid-β aggregation, and protein-tau-induced neurotoxicity were evaluated by using the experimental model C. elegans. AH exerted a high antioxidant capacity in vitro and in vivo. No toxicity was found in C. elegans at the dosages used. AH prevented ROS accumulation under AAPH-induced oxidative stress. Additionally, AH exerted a great anti-amyloidogenic capacity, which is relevant from the point of view of AD prevention. AH exacerbated the locomotive impairment in a C. elegans model of tauopathy, although the real contribution of AH remains unclear. The mechanisms under the observed effects might be attributed to an upregulation of daf-16 as well as to a strong ROS scavenging activity. These results increase the interest to study the biomedical applications of AH; however, more research is needed to deepen the mechanisms under the observed effects.

Characterization of Botanical Origin of Italian Honey by Carbohydrate Composition and Volatile Organic Compounds (VOCs)

Honey is a natural sweetener constituted by numerous macro- and micronutrients. Carbohydrates are the most representative, with glucose and fructose being the most abundant. Minor honey components like volatile organic compounds (VOCs), minerals, vitamins, amino acids are able to confer honey-specific properties and are useful to characterize and differentiate between honey varieties according to the botanical origin. The present work describes the chemical characterization of honeys of different botanical origin (multifloral, acacia, apple-dandelion, rhododendron, honeydew, and chestnut) produced and collected by beekeepers in the Trentino Alto-Adige region (Italy). Melissopalynological analysis was conducted to verify the botanical origin of samples and determine the frequency of different pollen families. The carbohydrate composition (fourteen sugars) and the profile of VOCs were evaluated permitting to investigate the relationship between pollen composition and the chemical profile of honey. Statistical analysis, particularly partial least squares discriminant analysis (PLS-DA), demonstrates the importance of classifying honey botanical origin on the basis of effective pollen composition, which directly influences honey's biochemistry, in order to correctly define properties and value of honeys.

Sensory and Compositional Properties Affecting the Likeability of Commercially Available Australian Honeys

Honey’s composition and appearance is largely influenced by floral and geographic origins. Australian honeys are frequently sourced from supermarkets; however, properties associated with consumer preference and likeability remain relatively unknown. The aim of this study was to complete sensory and compositional analyses on a selection of commercially available Australian honeys. Samples (n = 32) were analysed for visual, olfactory and taste characteristics, with overall likeability assessed by the trained sensory panel (n = 24; M = 12). Compositional analysis included colour intensity (mAU); phenolic content; antioxidant characteristics (DPPH, CUPRAC); and physicochemical properties (pH, viscosity, total soluble solids). There were 23 honey samples that were significantly less liked when compared to the most liked honey (p < 0.05). The likeability of honey was positively associated with perceived sweetness (p < 0.01), and it was negatively associated with crystallisation; odour intensity; waxy, chemical, and fermented smell; mouthfeel; aftertaste; sourness; bitterness and pH (All p’s < 0.05). The price (AUD/100 g) was not associated with likeability (p = 0.143), suggesting price value potentially does not influence consumer preferences. Conclusively, differences in likeability between the honey samples demonstrate that consumer perception of sampled honeys is diverse. Honey preference is primarily driven by the organoleptic properties, particularly perceived negative tastes, rather than their antioxidant capacity or phenolic content.

Effect of two different delivery systems of honey on the healing of oral ulcer in an animal model

Honey had several healing properties which includes antibacterial, anti-inflammatory and antioxidant properties. Hence, the aim of this study was to evaluate the effect of two different systems of honey on the healing of experimentally created traumatic oral ulcers in rats. Traumatic ulcers were created on the lower labial mucosa on male rats using 50% acetic acid. The rats were subsequently divided into three groups; in group one and two, the ulcers were treated with honey gel and honey adhesive respectively, whereas the third group received no treatment. The ulcers were macroscopically and microscopically studied. A statistical significant difference was observed in macroscopic investigation among the three groups in the 3rd and 7th day (p < 0.05). However, there were no statistical significant findings by the 15th day although a complete clinical healing was virtually observed in most of the cases. Histological examination shows a statistical significant difference within each of the three groups over time (p < 0.05). On the other hand, the mean rank values for the honey gel group were significantly higher in comparison to the other groups over time (p < 0.05). The therapeutic value of honey gel appears to be more effective than the mucoadhesive form in shortening the duration of wound healing.