Monitoring the total phenolic/antioxidant levels in wine using flow injection anaylsis with acidic potassium permanganate chemiluminescence detection

Flow injection methodology is described for the estimation of the total phenolic content of wine using acidic potassium permanganate chemiluminescence detection. Selected simple phenolic compounds including quercetin, rutin, catechin, epicatechin, ferulic acid, caffeic acid, gallic acid, 4-hydroxycinnamic acid and vanillin elicited analytically useful chemiluminescence with detection limits ranging between 4×10⁻¹⁰ and 7×10⁻⁷ M. A comparison between the chemiluminescence methodology and other total phenol/antioxidant assays, used by the food and beverage industry, resulted in a good correlation. The chemiluminescence detection was found to be selective with minimal interferences being observed from the non-phenolic components in wine. Analysis of 12 different wines showed that the chemiluminescence method was a rapid way to estimate their antioxidant or total phenolic content.

Biological activities of phenolic compounds present in virgin olive oil

The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet. Studies (human, animal, in vivo and in vitro) have demonstrated that olive oil phenolic compounds have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, antimicrobial activity and bone health. This paper summarizes current knowledge on the bioavailability and biological activities of olive oil phenolic compounds.

Molecular mechanisms of inflammation : anti-inflammatory benefits of virgin olive oil and the phenolic compound oleocanthal

Chronic inflammation is a critical factor in the pathogenesis of many inflammatory disease states including cardiovascular disease, cancer, diabetes, degenerative joint diseases and neurodegenerative diseases. Chronic inflammatory states are poorly understood, however it is known that dietary habits can evoke or attenuate inflammatory responses. Popular methods to deal with inflammation and its associated symptoms involve the use of non steroidal anti-inflammatory drugs, however the use of these drugs are associated with severe side effects. Therefore, investigations concerned with natural methods of inflammatory control are warranted. A traditional Mediterranean diet has been shown to confer some protection against the pathology of chronic diseases through the attenuation of proinflammatory mediators and this has been partially attributed to the high intake of virgin olive oil accompanying this dietary regime. Virgin olive oil contains numerous phenolic compounds that exert potent anti-inflammatory actions. Of interest to this paper is the recently discovered phenolic compound oleocanthal. Oleocanthal is contained in virgin olive oil and possesses similar anti-inflammatory properties to ibuprofen. This pharmacological similarity has provoked interest in oleocanthal and the few studies conducted thus far have verified its anti-inflammatory and potential therapeutic actions. A review of the health benefits of the Mediterranean diet and antiinflammatory properties of virgin olive oil is presented with the additional emphasis on the pharmacological and anti-inflammatory properties of the phenolic compound oleocanthal.

Antimicrobial, antioxidant and anti-inflammatory phenolic activities in extra virgin olive oil

The Mediterranean diet is associated with a lower incidence of chronic degenerative diseases and higher life expectancy. These health benefits have been partially attributed to the dietary consumption of extra virgin olive oil (EVOO) by Mediterranean populations, and more specifically the phenolic compounds naturally present in EVOO. Studies involving humans and animals (in vivo and in vitro) have demonstrated that olive oil phenolic compounds have potentially beneficial biological effects resulting from their antimicrobial, antioxidant and anti-inflammatory activities. This paper summarizes current knowledge on the biological activities of specific olive oil phenolic compounds together with information on their concentration in EVOO, bioavailability and stability over time.

Effect of compositional gradient on thermal behavior of synthetic graphite-phenolic nanocomposites

Synthetic graphite–phenolic nanocomposites were designed and synthesized with a compositional gradient which is shown to influence transient temperature fields during rapid temperature changes. Such nanocomposites were fabricated using a compression moulding technique, and thermal conductivity and heat capacity of nanocomposites were experimentally determined using a modified transient plane source technique over a wide temperature range from 253.15 to 373.15 K. The effects of four compositional gradient configurations on the transient temperature field across the thickness of a nanocomposite plate, at a high imposed temperature, was investigated. The transient time and temperature fields in nanocomposite structures were highly affected by the compositional gradient configurations.

Effect of sorghum flour addition on resistant starch content, phenolic profile and antioxidant capacity of durum wheat pasta

Foods containing elevated levels of health functional components such as resistant starch and polyphenolic antioxidants may have beneficial effects on human health. Pasta incorporating either red sorghum flour (RSF) or white sorghum flour (WSF) each at 20%, 30% and 40% substitution of durum wheat semolina (DWS) was prepared and compared to pasta made from 100% DWS (control) for content of starch fractions, phenolic profile and antioxidant capacity, before and after cooking. Total, digestible and resistant starch contents were determined by the AOAC method; individual phenolic acids and anthocyanins by reverse phase-HPLC analysis; total phenolic content by the Folin–Ciocalteu method and antioxidant capacity by the ABTS assay. The addition of both RSF and WSF increased the resistant starch content, bound phenolic acids, total phenolic content and antioxidant capacity at all incorporation levels compared to the control pasta; while free phenolic acids and anthocyanins were higher in the RSF-containing pasta only. Cooking did not change the resistant starch content of any of the pasta formulations. Cooking did however decrease the free phenolic acids, anthocyanins, total phenolic content and antioxidant capacity and increased the bound phenolic acids of the sorghum-containing pastas. The study suggests that these sorghum flours may be very useful for the preparation of pasta with increased levels of resistant starch and polyphenolic antioxidants.

Mechanical behaviour of functionally graded carbon nanofibre/phenolic nanocomposites: numerical modelling and experimental validation

In this study, a finite element-based model was developed to investigate the mechanical behaviour of functionally graded carbon nanofibre (CNF)/phenolic nanocomposites. Four functionally graded nanocomposites (FGNs), a non-graded nanocomposite (NGN), and a pure phenolic with the same geometry and total carbon nanofibre content were designed and fabricated. Flexural tests were conducted to validate the proposed finite element model. Close agreement was obtained between experimental results and numerical predictions. The results showed that flexural modulus can be improved about 45% by controlling the CNF content across the thickness of the samples.