Investigating 5-hydroxymethylfurfural formation kinetic and antioxidant activity in heat treated honey from different floral sources

Radiofrequency affects the decrystallization efficiency and physicochemical properties of rape honey via crystal structure modification and inactivating enzyme

Crystallization degrades the physicochemical properties of honey and reduces consumer acceptance. To address this issue, radiofrequency was developed to investigate the decrystallization efficiency and quality impact mechanism of rape honey. The results showed that radiofrequency significantly decreased the number and size of crystals, leading to shortening the decrystallization time to less than 10 min. The response surface optimization methodology further indicated that the highest decrystallization rate (98.72 ± 0.34 %) and lower 5-Hydroxymethylfurfural (2.45 ± 0.12 mg/kg) contents were obtained. Furthermore, radiofrequency changed the honey from a pseudoplastic into a Newtonian fluid efficiently due to the volumetric heating feature. It is worth noting that the inactivation of glucose oxidase reduced the antibacterial capacity, while the increase in total phenolic and flavonoid contents improved the antioxidant capacity of rape honey. In summary, current findings indicated that radiofrequency is a potential alternative decrystallization technology for water baths.

Physicochemical Characteristics, Phenolic Components, and Antioxidant Capacities of Lavender Honey (Lavandula Spp.) from Isparta Region of Türkiye

Lavender honey is one of the most desirable blossom honeys for its unique taste and aromatic qualities and can vary significantly from one region to another. In this study, melissopalynological, physicochemical and antioxidant properties of lavender honey from the Isparta region of Türkiye were investigated. The ration of the Lavandula spp. pollen were identified ranging from 9 % to 76 % in the thirteen samples. The average pH, conductivity, moisture, Hunter Lab* and proline values were 3.72, 0.22 mS/cm, 17.17 %, L*: 66.56, a*: 66.32, b*:18.41 and 576.92 mg/kg, respectively. The average F+G and F/G were 67.66 % and 1.02, respectively. The average of total phenolic (TP) and flavonoid (TF) substance were found to be 39.40 mg GAE/100 g and 3.23 mg QUE/100 g, respectively. The average total antioxidant capacity (FRAP) and DPPH radical scavenging activity values were found to be 178.28 μmol FeSO4 ⋅ 7H2O/100 g and 53.09 mg/mL, respectively. In the phenolic component analysis performed with HPLC-PDA, p-OH-benzoic acid, p-coumaric acid, chrysin and pinocembrin were detected as common polyphenols in the samples. Conclusively, despite considerable variability in their monofloral characteristics, no significant differences were observed in the physicochemical and antioxidant properties of lavender honeys.

Effect of Temperature and Time on the Physicochemical and Sensory Properties of Crystallized Honey

This research explores the crystallization process of honey during storage with a focus on its dissolution dynamics and essential characteristics. The investigation includes the examination of the effects of heat treatment at different temperatures (45-90 °C) and durations (23-960 min) on the induced crystallization of honey at 14 °C. Various analyses were conducted, including pH, acidity, color, sugar profile, phenolic and flavonoid contents, DPPH-scavenging activity, hydroxymethylfurfural (HMF), viscosity, and sensory attributes. The results indicated a reduction in the moisture content and pH, an increase in acidity, and higher levels of HMF at elevated temperatures. While the ash content remained relatively unchanged, variables such as color, glucose, fructose, total phenol, flavonoid, and antioxidant content exhibited variations with temperature. Viscosity decreased with an increase in temperature, suggesting Newtonian behavior and implying potential colloidal changes. Consumer sensory tests revealed significant differences among samples, with honey treated at 75 °C demonstrating superior physicochemical and sensory attributes. This study offers valuable insights into the dynamics of crystallized honey, providing information for both production practices and understanding consumer preferences.

Characterization of Turkish pine honey according to their geographical origin based on physicochemical parameters and chemometrics

This study was conducted to determine the characteristic properties of Turkish pine honey, which is an important honeydew honey. The geographical classification of the honey was determined by applying carbon isotope, melissopalynological, and physicochemical analyses to 373 samples collected from 47 regions between 2015 and 2017 under controlled conditions. δ13C protein-δ13Choney, C4%, electrical conductivity, moisture, ash, free acidity, color CIEL* a*b attributes, optical rotation [α]20, proline, diastases activities, and sugars (fructose, glucose, sucrose, and maltose) were used as physicochemical properties. Number of honeydew elements /number of total pollen (NHE/NTP) ratios were studied at melissopalynological analyses. The results showed that all samples exhibited honeydew properties, and that all physicochemical parameters met the criteria set by regulatory standards for honeydew. However, C4% sugar and δ13C protein-δ13C honey values did not meet the regulatory criteria and exhibited quite wide standard deviations.

A Simple High-Throughput Field Sample Preparation Method Based on Matrix-Induced Sugaring-Out for the Simultaneous Determination of 5-Hydroxymethylfurfural and Phenolic Compounds in Honey

In the present work, a high-throughput field sample preparation method was reported for the simultaneous determination of 5-hydroxymethylfurfural and phenolic compounds in honey. Combining a simple and green homogenous liquid−liquid extraction, matrix-induced sugaring-out, with the use of a 96-deepwell plate and multichannel pipette, the proposed method showed its merits in instrument-free and high-throughput preparation. Due to the high-throughput property, the parameters of the method were rapidly and systematically studied using a constructed 4 × 2 × 4 × 3 array (sample amount × ratio of ACN:H2O × standing time × replicates) in a 96-deepwell plate. Analytical performance was fully validated, and the limits of detection and limits of quantification were in the range of 0.17−1.35 μg/g and 0.51−4.14 μg/g, respectively. Recoveries were between 83.98 and 117.11%, and all the precisions were <5%. Furthermore, the developed method was successfully applied in the outdoor preparation of commercial honey samples and the in-field preparation of raw honey samples in apiary. The current work presented a simple, rapid, and high-throughput method for the field sample preparation of honey and provides a valuable strategy for the design of field and on-site sample preparation.

Physicochemical characteristics, antioxidant properties and bacterial profiling of three Malaysian honey varieties: a study using multivariate analysis

BACKGROUND

The physicochemical characteristics, antioxidant properties, and bacterial profiles of Heterotrigona itama, Apis dorsata, and Apis mellifera honey of Malaysian origin were studied and the results were assessed using Pearson correlation analysis and canonical correspondence analysis (CCA).

RESULTS

The analysis showed that the Mellifera honey was characterized by high total sugar content (717.5 g kg^-1 ); the Itama honey was characterized by high free acidity (347.5 meq kg^-1 ); and the Dorsata honey was characterized by high radical scavenging activity (RSA; 69.3%RSA), total phenolic content (TPC; 1284.5 mg GAE kg^-1 ) and hydroxymethylfurfural (HMF; 51.5 mg kg^-1 ). Pearson correlation analysis showed that the TPC was positively correlated with HMF as well as RSA. The bacterial profile of Mellifera honey was significantly less diverse than Itama and Dorsata honey. Mellifera and Itama honey seemed to harbour a significant abundance of lactic acid bacteria, with relative abundance of 0.339 and 0.195, which suggests that it possesses probiotic potential. The Dorsata honey, however, contained pathogenic Clostridium genus, constituting 5% of its bacterial profile.

CONCLUSION

The characteristic properties of the three investigated honey, Itama, Dorsata, and Mellifera were identified. The distinctive characteristics of the honey varieties informed the development of appropriate processing strategies for retaining the beneficial qualities of raw honey. It is hoped that the results of this study will shine light on Malaysian honey in a highly competitive global market. © 2022 Society of Chemical Industry.

Classification of Polish Natural Bee Honeys Based on Their Chemical Composition

The targeted quantitative NMR (qNMR) approach is a powerful analytical tool, which can be applied to classify and/or determine the authenticity of honey samples. In our study, this technique was used to determine the chemical profiles of different types of Polish honey samples, featured by variable contents of main sugars, free amino acids, and 5-(hydroxymethyl)furfural. One-way analysis of variance (ANOVA) was performed on concentrations of selected compounds to determine significant differences in their levels between all types of honey. For pattern recognition, principal component analysis (PCA) was conducted and good separations between all honey samples were obtained. The results of present studies allow the differentiation of honey samples based on the content of sucrose, glucose, and fructose, as well as amino acids such as tyrosine, phenylalanine, proline, and alanine. Our results indicated that the combination of qNMR with chemometric analysis may serve as a supplementary tool in specifying honeys.

A chemometric approach for the differentiation of 15 monofloral honeys based on physicochemical parameters

BACKGROUND

Although the main method for authentication of monofloral honey is pollen analysis, other classification approaches have been also applied. However, the majority of the existing classification models so far have utilized a few honey types or a few honey samples of each honey type, which can lead to inaccurate results. Aiming at addressing this, the goal of the present study was to create a classification model by analysing in total 250 honey samples from 15 different monofloral honey types in ten physicochemical parameters and then, multivariate analysis [multivariate analysis of variance (MANOVA), principal component analysis (PCA) and multi-discriminant analysis (MDA)] was applied in an effort to distinguish and classify them.

RESULTS

Electrical conductivity and colour were found to have the highest discriminative power, allowing the classification of monofloral honey types, such as oak, knotgrass and chestnut honey, as well as the differentiation between honeydew and nectar honeys. The classification model had a high predictive power, as the 84.4% of the group cases was correctly classified, while for the cases of chestnut, strawberry tree and sunflower honeys the respective prediction was correct by 91.3%, 95% and 100%, allowing further determination of unknown honey samples.

CONCLUSION

It seems that the characterization of monofloral honeys based on their physicochemical parameters through the proposed model can be achieved and further applied on other honey types. The results could contribute to the development of methodologies for the determination of honey's botanical origin, based on simple techniques, so that these can be applied for routine analysis. © 2021 Society of Chemical Industry.

Bioconversion of agro-industry sourced biowaste into biomaterials via microbial factories - A viable domain of circular economy

Global increase in demand for food supply has resulted in surplus generation of wastes. What was once considered wastes, has now become a resource. Studies were carried out on the conversion of biowastes into wealth using methods such as extraction, incineration and microbial intervention. Agro-industry biowastes are promising sources of carbon for microbial fermentation to be transformed into value-added products. In the era of circular economy, the goal is to establish an economic system which aims to eliminate waste and ensure continual use of resources in a close-loop cycle. Biowaste collection is technically and economically practicable, hence it serves as a renewable carbon feedstock. Biowastes are commonly biotransformed into value-added materials such as bioethanol, bioplastics, biofuels, biohydrogen, biobutanol and biogas. This review reveals the recent developments on microbial transformation of biowastes into biotechnologically important products. This approach addresses measures taken globally to valorize waste to achieve low carbon economy. The sustainable use of these renewable resources is a positive approach towards waste management and promoting circular economy.

Cocoa Shell as a Step Forward to Functional Chocolates-Bioactive Components in Chocolates with Different Composition

Chocolate is considered as both caloric and functional food. Its nutritional properties may be improved by addition of fiber; however, this may reduce polyphenols content. The aim of this research was to determine the influence of cocoa shell addition (as a source of fiber) and its combination with different ingredients (cocoa butter equivalents (CBE), emulsifiers, dairy ingredients) on polyphenols of dark and milk chocolates. Total polyphenol (TPC) and total flavonoid (TFC) contents were determined spectrophotometrically, identification and quantification of individual compounds by high pressure liquid chromatography and antioxidant capacity by ferric reducing antioxidant power (FRAP) assay. Results showed that even though addition of cocoa shell to chocolate results in reduced contents of TPC, TFC, and individual compounds, it is not significant compared to ones reported by other authors for commercial chocolates. Other ingredients influence determined values for all investigated parameters; however, additional research is needed to reveal exact mechanisms and implications.