scholarly journals Electrochemical Determination of the “Furanic Index” in Honey

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4115
Author(s):  
Severyn Salis ◽  
Nadia Spano ◽  
Marco Ciulu ◽  
Ignazio Floris ◽  
Maria I. Pilo ◽  
...  

5-(hydroxymethyl)furan-2-carbaldehyde, better known as hydroxymethylfurfural (HMF), is a well-known freshness parameter of honey: although mostly absent in fresh samples, its concentration tends to increase naturally with aging. However, high quantities of HMF are also found in fresh but adulterated samples or honey subjected to thermal or photochemical stresses. In addition, HMF deserves further consideration due to its potential toxic effects on human health. The processes at the origin of HMF formation in honey and in other foods, containing saccharides and proteins—mainly non-enzymatic browning reactions—can also produce other furanic compounds. Among others, 2-furaldehyde (2F) and 2-furoic acid (2FA) are the most abundant in honey, but also their isomers (i.e., 3-furaldehyde, 3F, and 3-furoic acid, 3FA) have been found in it, although in small quantities. A preliminary characterization of HMF, 2F, 2FA, 3F, and 3FA by cyclic voltammetry (CV) led to hypothesizing the possibility of a comprehensive quantitative determination of all these compounds using a simple and accurate square wave voltammetry (SWV) method. Therefore, a new parameter able to provide indications on quality of honey, named “Furanic Index” (FI), was proposed in this contribution, which is based on the simultaneous reduction of all analytes on an Hg electrode to ca. −1.50 V vs. Saturated Calomel Electrode (SCE). The proposed method, validated, and tested on 10 samples of honeys of different botanical origin and age, is fast and accurate, and, in the case of strawberry tree honey (Arbutus unedo), it highlighted the contribution to the FI of the homogentisic acid (HA), i.e., the chemical marker of the floral origin of this honey, which was quantitatively reduced in the working conditions. Excellent agreement between the SWV and Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC) data was observed in all samples considered.

2021 ◽  
Vol 45 (6) ◽  
pp. 3215-3223
Author(s):  
Selvarasu Maheshwaran ◽  
Ramachandran Balaji ◽  
Shen-Ming Chen ◽  
Ray Biswadeep ◽  
Vengudusamy Renganathan ◽  
...  

A high-performance electrochemical sensing platform based on CuS nano-globules is efficiently developed.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4889 ◽  
Author(s):  
Evangelia Kritikou ◽  
Natasa P. Kalogiouri ◽  
Lydia Kolyvira ◽  
Nikolaos S. Thomaidis

The huge interest in the health-related properties of foods to improve health has brought about the development of sensitive analytical methods for the characterization of natural products with functional ingredients. Greek olive leaves and drupes constitute a valuable source of biophenols with functional properties. A novel ultra-high-performance liquid chromatography–quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method was developed to identify biophenols through target and suspect screening in Greek olive leaves and drupes of the varieties: Koroneiki, Throumbolia, Konservolia, Koutsourelia, Kalamon, Petrolia, Amigdalolia, Megaritiki, Mastoeidis, Agouromanakolia, Agrilia, Adramitiani and Kolovi. The method’s performance was evaluated using the target compounds: oleuropein, tyrosol and hydroxytyrosol. The analytes demonstrated satisfactory recovery efficiency for both leaves (85.9–90.5%) and drupes (89.7–92.5%). Limits of detection (LODs) were relatively low over the range 0.038 (oleuropein)–0.046 (hydroxytyrosol) and 0.037 (oleuropein)–0.048 (hydroxytyrosol) for leaves and drupes, respectively For leaves, the precision limit ranged between 4.7% and 5.8% for intra-day and between 5.8% and 6.5% for inter-day experiments, and for drupes, it ranged between 3.8% and 5.2% for intra-day and between 5.1 and 6.2% for inter-day experiments, establishing the good precision of the method. The regression coefficient (r2) was above 0.99 in all cases. Furthermore, the preparation of herbal tea from olive leaves is suggested after investigating the optimum infusion time of dried leaves in boiling water. Overall, 10 target and 36 suspect compounds were determined in leaves, while seven targets and thirty-three suspects were identified in drupes, respectively.


1999 ◽  
Vol 5 (2) ◽  
pp. 121-137 ◽  
Author(s):  
R. López-Fandiño ◽  
A. Olano

Selected indicators of the quality of processed milk are reviewed in three sections: indices of heat treatment, detection of adulterations and assessment of shelf life. The characterization of the thermal process to which milk was submitted can be achieved by measuring either the formation of new compounds (lactulose, furosine) or the degradation of thermolabile constituents (enzymes, whey proteins). The presence of certain compounds may indicate fraudulent additions committed for eco nomic reasons. Finally, residual or reactivated heat stable enzymes may cause serious storage defects in UHT milk and, therefore, the proteolytic and lipolytic activities and the degree of protein and lipid degradation are useful predictors of the shelf life. Different analytical methods for the determination of the selected quality indicators are also summarized.


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