Suitability of lemon balm (Melissa officinalis L.) extract rich in rosmarinic acid as a potential enhancer of functional properties in cupcakes.

Melissa officinalis (lemon balm) and its extracts have been frequently reported as possessing bioactive properties, offering the potential for use in development/enrichment of food products with additional functional capabilities, providing health benefits to consumers. The antioxidant, antibacterial and antifungal activity of lemon balm extract, as well as its potential hepatotoxicity were thoroughly evaluated. The extracts were then incorporated into cupcakes and their preserving effect, chemical composition, colour parameters and antioxidant activity were compared with those provided by potassium sorbate. In general, the variables with the largest differences among different storage times were energy level, sucrose, glucose, palmitic acid (C6:0) and oleic acid (C18:1n9). On the other hand, L∗ (top), a∗ (top), b∗ (top), pH, capric acid (C10:0) and lauric acid (C12:0) showed the greatest variation according to cupcake formulation. The results observed indicate that the lemon balm extract rich in rosmarinic acid can provide advantageous functional properties to bakery products.

Evaluation of the QuEChERS sample preparation approach for the analysis of pesticide residues in olives.

This paper describes the use of a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for extraction and cleanup of 16 pesticide residues of interest in olives and olive oil. These products contain a high lipid content, which can adversely affect pesticide recoveries and harm traditional chromatographic systems. For extraction, the main factors (oil and water content) were studied and optimized in experiments to maximize pesticide recoveries. Dispersive SPE with different sorbents was also investigated to minimize matrix coextractives and interferences. For analysis, a new automated DSI device was tested in GC-MS to avoid nonvolatile coextractives from contaminating the instrument. LC-MS/MS with positive ESI was used for those pesticides that were difficult to detect by GC-MS. The final method was validated for olives in terms of recoveries, repeatabilities, and reproducibilities using both detection techniques. The results demonstrated that the method achieved acceptable quantitative recoveries of 70-109% with RSDs < 20% for DSI-GC-MS and 88-130% with RSDs < 10% for LC-MS/MS, and LOQ at or below the regulatory maximum residue limits for the pesticides were achieved.

Comparison of matrix solid-phase dispersion and liquid-liquid extraction for the chromatographic determination of fenthion and its metabolites in olives and olive oils.

Matrix solid-phase dispersion (MSPD) methodology has been developed to extract fenthion and its metabolites from olives and olive oils, and the technique compared with conventional liquid-liquid extraction (LLE). The method was applied to olives and olive oil samples obtained from olive groves treated with fenthion. Pesticide residues were analysed by gas chromatography (GC) using a nitrogen-phosphorus detector. Both extraction methods gave a linear response over the concentration range assayed (0.03-1 mg kg-1 for MSPD and 0.1-1 mg kg-1 for LLE). Recoveries and RSD (n = 6) values in olives were 85-112% and 2-6% for MSPD, and 68-108% and 4-16% for LLE, respectively. In the case of olive oil, recoveries and RSD (n = 6) values were 67-98% and 5-11% for MSPD, and 63-115% and 6-14% for LLE, respectively. When compared to LLE, the newly developed MSPD method was twice as sensitive and required 10 times less sample weight.