Comprehensive identification and distribution pattern of 37 oxygenated heterocyclic compounds in commercially important citrus juices

Determination of Oxygen Heterocyclic Compounds in Foods Using Supercritical Fluid Chromatography-Tandem Mass Spectrometry

The aim of this research was to determine oxygen heterocyclic compounds in twenty-six Citrus- and cinnamon-flavoured foods using supercritical fluid chromatography in combination with triple-quadrupole mass spectrometry (SFC-QqQ-MS). According to the authors' knowledge, this is the first report on the determination of these molecules in foods by means of the SFC-QqQ-MS technique. The analytical technique normally used for their determination in foods is liquid chromatography coupled with a photodiode array detector. However, supercritical fluid chromatography is proving to be a valid alternative approach to investigating coumarins, furocoumarins and polymethoxyflavones. According to the results presented herein, each sample analysed showed the presence of molecules of interest. Coumarin was found in all the cinnamon-flavoured samples analysed in a low concentration. The presence of oxygen heterocyclic compounds in all the Citrus-flavoured samples, according to the label, comfirmed that the foods selected for this research article were prepared with Citrus fruits. Among the samples analysed, mandarin juice was the richest in bioactive compounds, representing a good source of polymethoxyflavones in a diet.

Targeted Metabolomics With a Chemometric Study of Oxygenated Heterocyclic Aglycones as a Tool for Preliminary Authenticity Assessment of Orange and Grapefruit Juices

Profiles of citrus juice oxygenated heterocyclic aglycones (OHAs), which are notable marker secondary metabolites, were used to assess the authenticity of sweet orange and grapefruit juices in situations where mandarin and pomelo juices might be adulterants. Thirty-nine known OHAs, including 10 methoxyflavones, 13 coumarins, and 16 furanocoumarins, as well as 13 tentatively screened OHAs, were analyzed in orange, mandarin, grapefruit and pomelo juices using our newly developed high-resolution HPLC-UV and fluorescence detection method. Quantitative OHA profiles from 158 pure juice samples were obtained to establish a purity discriminant model using an omics strategy. Reduction of OHA variables showed that three important methoxyflavones, i.e. isosinensetin, tangeretin and sinensetin provided the best discrimination ability between sweet orange and mandarin juices. There are two subtypes of pomelos, Shatianyou Group and Wendan Group, of which juices should be separately compared to grapefruit juice. Five OHAs, namely meranzin, 3,5,6,7,8,3',4'-heptamethoxyflavone, osthole, 6',7'-epoxybergamottin, and bergamottin were found to discriminate Shatianyou Group of pomelo juice from grapefruit juice; whereas three OHAs, namely bergaptol, isomeranzin, and 6',7'-dihydroxybergamottin were able to discriminate Wendan Group of pomelo juice from grapefruit juice. The established partial least squares discriminant analysis (PLS-DA) models were capable of detecting as little as 10% mandarin juice in sweet orange juice and 10% pomelo juice in grapefruit juice, allowing for fast prescreening of excess addition with good reliability (root mean square error of prediction, RMSEP < 5%).

Anti-obesity effect of fermented lemon peel on high-fat diet-induced obese mice by modulating the inflammatory response

Inflammation is a characteristic of obesity. The rich compounds in lemon peel have anti-inflammatory effects. This study examined whether fermented lemon peel can have an anti-obesity effect on obese mice induced by a high-fat diet (HFD) by regulating inflammation. The lemon peel fermentation supernatant (LPFS) could inhibit the weight gain of mice and improve the lesions of the liver and epididymal adipose tissue. In addition, LPFS regulates blood lipids, liver function, and inflammation-related indicators in the serum of obese mice. LPFS plays a positive role in regulating the inflammation and obesity-related genes in liver tissue and adipose tissue of obese mice. High-performance liquid chromatography showed an increase in the contents of compounds with antioxidant or/and anti-inflammatory effects and compounds with anti-obesity effects. These results suggest that the LPFS could help reduce obesity in obese mice induced by an HFD by adjusting the balance of the inflammatory response. PRACTICAL APPLICATIONS: Obesity often increases the risk of chronic diseases, and mild inflammation is a feature of obesity. Therefore, timely suppression of inflammation in the body can help control the occurrence of obesity. This study clarified the anti-obesity effect of fermented lemon peel on a high-fat diet (HFD)-induced obese mice by regulating the body's inflammatory response and confirmed that fermentation improves the anti-inflammatory activity of lemon peel. This study provides important references for future investigation, prophylaxis, and treatment of inflammation and obesity-related diseases, as well as the advances in functional foods and fermented foods with anti-inflammatory and anti-obesity activities.