Quantitation of Sterols and Steryl Esters in Fortified Foods and Beverages by GC/FID

The Lack of Standardization and Pharmacological Effect Limits the Potential Clinical Usefulness of Phytosterols in Benign Prostatic Hyperplasia

The prevalence of benign prostatic hyperplasia (BPH) markedly increases with age. Phytotherapeutic approaches have been developed over time owing to the adverse side effects of conventional medications such as 5-reductase inhibitors and α1-adrenergic receptor antagonists. Therefore, dietary supplements (DS) containing active compounds that benefit BPH are widely available. Phytosterols (PSs) are well recognized for their role in maintaining blood cholesterol levels; however, their potential in BPH treatment remains unexplored. This review aims to provide a general overview of the available data regarding the clinical evidence and a good understanding of the detailed pharmacological roles of PSs-induced activities at a molecular level in BPH. Furthermore, we will explore the authenticity of PSs content in DS used by patients with BPH compared to the current legislation and appropriate analytical methods for tracking DS containing PSs. The results showed that PSs might be a useful pharmacological treatment option for men with mild to moderate BPH, but the lack of standardized extracts linked with the regulation of DS containing PSs and experimental evidence to elucidate the mechanisms of action limit the use of PSs in BPH. Moreover, the results suggest multiple research directions in this field.

Fermented camel milk enriched with plant sterols improves lipid profile and atherogenic index in rats fed high -fat and -cholesterol diets

The current study was designed to explore the effect of fermented camel milk, plant sterols and their combination on the blood levels of sd-LDL and atherogenicity in rats fed on high-fat-cholesterol diets (HFC). Forty male Wistar rats were distributed into five groups: Normal control (NC), Positive control (PC, HFC), plant sterol (PS, HFC containing 1% (w/w) β-sitosterol:Stigmasterols; 9:1), FM (HFC containing 4% (w/w) lyophilized fermented camel milk), and PSFM (HFC containing 1% (w/w) plant sterols +4% (w/w) lyophilized fermented camel milk). Antioxidant activity showed that β-sitosterol had the highest radical scavenging activity, followed by fermented camel milk and stigmasterol (p < 0.05). Feeding rats on HFC for 8 weeks resulted in a significant (p < 0.05) increase in blood lipids of PC group compared with NC group. Administration of PS, FM, and PSFM resulted in a significant reduction in atherogenic index (50, 24.5, and 41.5 %, p < 0.05), and sd-LDL levels (73, 45, and 59%, p < 0.05), respectively. Only the FM group showed a significant reduction in triglycerides levels of rats. Administration of PS, FM and PSFM decreased serum MDA levels significantly by 58.7, 45.4, and 69% (p < 0.05), and increased total antioxidant capacity by 35.9, 84.8, and 38.3% (p < 0.05), respectively. This is the first report to the best of our knowledge that shows fermented camel milk enriched with plant sterol could reduce atherogenesis and cardiovascular diseases activity via inhibition of the status of small dense LDL and oxidative stress.

Rapid measurement of phytosterols in fortified food using gas chromatography with flame ionization detection

A novel method for the measurement of total phytosterols in fortified food was developed and tested using gas chromatography with flame ionization detection. Unlike existing methods, this technique is capable of simultaneously extracting sterols during saponification thus significantly reducing extraction time and cost. The rapid method is suitable for sterol determination in a range of complex fortified foods including milk, cheese, fat spreads, oils and meat. The main enhancements of this new method include accuracy and precision, robustness, cost effectiveness and labour/time efficiencies. To achieve these advantages, quantification and the critical aspects of saponification were investigated and optimised. The final method demonstrated spiked recoveries in multiple matrices at 85-110% with a relative standard deviation of 1.9% and measurement uncertainty value of 10%.

Plant sterols and antioxidant parameters in enriched beverages: storage stability

Plant sterols (PS) stability, antioxidant parameters, and color were studied during 6 months of storage at 4, 24, and 37 °C in three PS-enriched functional beverages. Beverages were skimmed milk with fruit juice and PS (MFJPS), fruit juice and PS (FJPS), and skimmed milk with PS (MPS). No loss in total PS content occurred during storage observing the same values at any given storage time point. Total carotenoids decreased 36% with storage at two months and then remained stable. Total polyphenols showed fluctuations throughout the storage, remaining stable at 6 months and reaching initial values. The antioxidant capacity (TEAC method) increased 18% at 6 months, and there was an increase in color over time and temperature, probably due to Maillard reaction compound formation. The increase in total antioxidant capacity might have helped PS maintenance throughout storage, these beverages being a good PS source even after 6 months of storage.

GC-based analysis of plant stanyl fatty acid esters in enriched foods

Approaches for the capillary gas chromatographic (GC) based analysis of intact plant stanyl esters in enriched foods were developed. Reference compounds were synthesized by enzyme-catalyzed transesterifications. Their identities were confirmed by means of mass spectrometry. Using a medium polar trifluoropropylmethyl polysiloxane stationary phase, long-chain plant stanyl esters could be separated according to their stanol moieties and their fatty acid chains. Thermal degradation during GC analysis was compensated by determining response factors; calibrations were performed for ten individual plant stanyl esters. For the analysis of low-fat products (skimmed milk drinking yogurts), the GC separation was combined with a "fast extraction" under acidic conditions. For fat-based foods (margarines), online coupled LC-GC offered an elegant and efficient way to avoid time-consuming sample preparation steps. The robust and rapid methods allow conclusions on both, the stanol profiles and the fatty acid moieties, and thus provide a basis for the authentication of this type of functional food ingredients.