Emilio Alvarez-Parrilla

Antioxidant activity of fresh and processed Jalapeño and Serrano peppers.

In this research, total phenols, flavonoids, capsaicinoids, ascorbic acid, and antioxidant activity (ORAC, hydroxyl radical, DPPH, and TEAC assays) of fresh and processed (pickled and chipotle canned) Jalapeño and Serrano peppers were determined. All fresh and processed peppers contained capsaicin, dihydrocapsaicin, and nordihydrocapsaicin, even though the latter could be quantified only in fresh peppers. Processed peppers contained lower amounts of phytochemicals and had lower antioxidant activity, compared to fresh peppers. Good correlations between total phenols and ascorbic acid with antioxidant activity were observed. Elimination of chlorophylls by silicic acid chromatography reduced the DPPH scavenging activity of the extracts, compared to crude extracts, confirming the antioxidant activity of chlorophylls present in Jalapeño and Serrano peppers.

Structural Stability and Viability of Microencapsulated Probiotic Bacteria: A Review

Probiotics are live microorganisms that confer a number of health benefits when consumed in adequate amounts, mostly due to improvement of intestinal microflora. Bacterial strains from the genera Lactobacillus, Bifidobacterium, and Bacillus have been widely studied and are used to prepare ready-to-eat foods. However, the physicochemical stability and bioavailability of these bacteria have represented a challenge for many years, particularly in nonrefrigerated foodstuffs. Microencapsulation (ME) helps to improve the survival of these bacteria because it protects them from harsh conditions, such as high temperature, pH, or salinity, during the preparation of a final food product and its gastrointestinal passage. The most common coating materials used in the ME of probiotics are ionic polysaccharides, microbial exopolysaccharides, and milk proteins, which exhibit different physicochemical features as well as mucoadhesion. Structurally, the survival of improved bacteria depends on the quantity and strength of the functional groups located in the bacterial cell walls, coating materials, and cross-linkers. However, studies addressing the role of these interacting groups and the resulting metabolic impacts are still scarce. The fate of new probiotic-based products for the 21st century depends on the correct selection of the bacterial strain, coating material, preparation technique, and food vehicle, which are all briefly reviewed in this article.

Phenolic Compounds and Antioxidant Activity of Kernels and Shells of Mexican Pecan (Carya illinoinensis)

The phenolic composition and antioxidant activity of pecan kernels and shells cultivated in three regions of the state of Chihuahua, Mexico, were analyzed. High concentrations of total extractable phenolics, flavonoids, and proanthocyanidins were found in kernels, and 5-20-fold higher concentrations were found in shells. Their concentrations were significantly affected by the growing region. Antioxidant activity was evaluated by ORAC, DPPH•, HO•, and ABTS•-- scavenging (TAC) methods. Antioxidant activity was strongly correlated with the concentrations of phenolic compounds. A strong correlation existed among the results obtained using these four methods. Five individual phenolic compounds were positively identified and quantified in kernels: ellagic, gallic, protocatechuic, and p-hydroxybenzoic acids and catechin. Only ellagic and gallic acids could be identified in shells. Seven phenolic compounds were tentatively identified in kernels by means of MS and UV spectral comparison, namely, protocatechuic aldehyde, (epi)gallocatechin, one gallic acid-glucose conjugate, three ellagic acid derivatives, and valoneic acid dilactone.

Preserving quality of fresh-cut products using safe technologies.

Food preservation is critical for keeping the global food supply safe and available for consumers. Food scientists study production and processing to develop new technologies that improve the quality and quantity of healthy food products, with the main objective of increasing food production without affecting food quality and environment, while fulfilling consumer expectations. Nowadays consumers want their food to be fresh, nutritious, safe, and attractive, low priced, and ready-to-eat. That is the case of fresh-cut products; however, maintaining the quality of these products is not an easy task, since minimally processed products experience increased ethylene production and respiration rates, with the consequent lost of quality. New effective and inexpensive technologies to safely preserve the quality of fresh-cut products are needed. In the last two decades, food scientists have attempted to solve problems in fresh-cut processing and quality preservation, and rapid advances in scientific knowledge on fresh-cut product preservation have been developed. The present review describes the use of emerging technologies such as ultraviolet irradiation (UV-C), edible coatings, active packaging and natural additives, to preserve the quality of fresh-cut fruits; highlighting the areas in which information is still lacking, and commenting on future trends.

Daily consumption of apple, pear and orange juice differently affects plasma lipids and antioxidant capacity of smoking and non-smoking adults

Abstract Epidemiological studies have shown an inverse correlation between a fruit and vegetable-rich diet and cardiovascular diseases; this beneficial effect of fruits and vegetables is probably due to the presence of antioxidant phytochemicals. In contrast, cigarette smoking is a high risk factor for lung and heart diseases, associated with chronic oxidative stress. In the present study, the effect of the consumption of a pear, an apple and 200 ml orange juice, during 26 days, on total plasma antioxidant capacity (TAC) and lipid profile of chronic smokers and non-smoking healthy adults was analyzed. Fruit consumption increased TAC in non-smokers, but not in smokers. In non-smokers, total cholesterol, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol increased significantly; while in smokers, total cholesterol and low-density lipoprotein-cholesterol decreased. We may conclude fruit/juice supplementation showed different effects, depending on the smoking habit: in non-smokers it increased TAC and cholesterol; in smokers it reduced cholesterol, whithout inducing a TAC increase.

Cyanidin-3-O-glucoside: Physical-Chemistry, Foodomics and Health Effects

Anthocyanins (ACNs) are plant secondary metabolites from the flavonoid family. Red to blue fruits are major dietary sources of ACNs (up to 1 g/100 g FW), being cyanidin-3-O-glucoside (Cy3G) one of the most widely distributed. Cy3G confers a red hue to fruits, but its content in raspberries and strawberries is low. It has a good radical scavenging capacity (RSC) against superoxide but not hydroxyl radicals, and its oxidative potential is pH-dependent (58 mV/pH unit). After intake, Cy3G can be metabolized (phases I, II) by oral epithelial cells, absorbed by the gastric epithelium (1%–10%) and it is gut-transformed (phase II & microbial metabolism), reaching the bloodstream (<1%) and urine (about 0.02%) in low amounts. In humans and Caco-2 cells, Cy3G’s major metabolites are protocatechuic acid and phloroglucinaldehyde which are also subjected to entero-hepatic recycling, although caffeic acid and peonidin-3-glucoside seem to be strictly produced in the large bowel and renal tissues. Solid evidence supports Cy3G’s bioactivity as DNA-RSC, gastro protective, anti-inflammatory, anti-thrombotic chemo-preventive and as an epigenetic factor, exerting protection against Helicobacter pylori infection, age-related diseases, type 2 diabetes, cardiovascular disease, metabolic syndrome and oral cancer. Most relevant mechanisms include RSC, epigenetic action, competitive protein-binding and enzyme inhibition. These and other novel aspects on Cy3G’s physical-chemistry, foodomics, and health effects are discussed.

The pecan nut (Carya illinoinensis) and its oil and polyphenolic fractions differentially modulate lipid metabolism and the antioxidant enzyme activities in rats fed high-fat diets

Tree nuts such as pecans (Carya illinoinensis) contain mostly oil but are also a source of polyphenols. Nut consumption has been linked to a reduction in serum lipid levels and oxidative stress. These effects have been attributed to the oil while overlooking the potential contribution of the polyphenols. Because the evidence regarding each fractions bioactivity is scarce, we administered high-fat (HF) diets to male Wistar rats, supplementing them with pecan oil (HF+PO), pecan polyphenols (HF+PP) or whole pecans (HF+WP), and analysed the effects of each fraction. The HF diet increased the serum leptin and total cholesterol (TC) with respect to the control levels. The HF+WP diet prevented hyperleptinemia and decreased the TC compared with the control. The HF+WP diet upregulated the hepatic expression of apolipoprotein B and LDL receptor mRNAs with respect to the HF levels. The HF+PO diet reduced the level of triacylglycerols compared with the control. The HF+PP diet stimulated the hepatic expression of liver X receptor alpha mRNA. The HF+WP diet increased the activities of hepatic catalase, glutathione peroxidase and glutathione S transferase compared with the control, and decreased the degree of lipid peroxidation compared with the HF diet. The most bioactive diet was the WP diet.

TOTAL PHENOLS AND ANTIOXIDANT ACTIVITY OF COMMERCIAL AND WILD MUSHROOMS FROM CHIHUAHUA, MEXICO FENOLES TOTALESY CAPACIDAD ANTIOXIDANTE DE HONGOS COMERCIALESY SILVESTRES DE CHIHUAHUA, MÉXICO

Abstract Three wild edible mushrooms (Agaricus sp., Boletus sp., and Macrolepiota sp.) from the North of Mexico (Chihuahua state) and two commercial species (Agaricus bisporus white strain and Portabella: Agaricus bisporus brown strain) were analyzed to determine their proximate composition, total phenols and antioxidant activity. Wild mushrooms presented lower humidity values with respect to commercial species. Other proximate parameters such as total protein, lipids, ashes and carbohydrates were similar to those reported for edible mushrooms. Total phenols and antioxidant activity (Ferric Reducing/Antioxidant Power assay, FRAP) were determined from 80% methanol extracts. Wild Mushrooms had higher phenol content and antioxidant capacity than commercial mushrooms. A direct correlation between phenols and antioxidant activity (r2 = 0.986) was observed. Due to these characteristics, wild mushrooms could be considered as a complement in the diet for the health benefits they present. Resumen Se analizó la composición proximal, fenoles totales y capacidad antioxidante, de tres hongos silvestres (Agaricus sp., Boletus sp., and Macrolepiota sp.) del norte de México (Chihuahua) y dos comerciales (Agaricus bisporus cepa blanca and Portalella: Agaricus bisporus cepa café). Los hongos silvestres presentaron valores menores de humedad que los comerciales. Los demás parámetros proximales (proteínas, lípidos, cenizas y carbohidratos totales) fueron similares a los reportados para hongos silvestres. La concentración de fenoles totales y actividad antioxidante (Ferric Reducing/Antioxidant Power assay, FRAP) se determinaron a partir de extractos con metanol al 80%. Los hongos silvestres presentaron valores más altos en fenoles totales y actividad antioxidante, frente a los hongos comerciales. Se observó una correlación directa (r2 = 0,986) entre fenoles totales y actividad antioxidante. Estas características de los hogos silvestres hacen que puedan ser considerados, como complemento de la dieta ya que puede presentar buenos beneficios en la salud. Palabras clave: Hongos comestibles, análisis proximal, polifenoles, actividad antioxidante, FRAP

COMPUESTOS POLIFENÓLICOS Y CAPACIDAD ANTIOXIDANTE DE ESPECIAS TÍPICAS CONSUMIDAS EN MÉXICO

Spices are aromatic plants that have been widely used in Mexico to preserve or seasoning different foods, but have also been used as herbal remedies to cure some diseases. These culinary and medicinal properties of spices have been attributed to several food components, including phytochemicals. Among them, polyphenolic compounds have been extensively studied for their effect against several chronic and degenerative diseases, probably due to their antioxidant activity. The study of the antioxidant capacity of Mexican spices may lead to new research on the potential benefits of these spices on human health. This paper analyzes the main studies on the potential beneficial effects of traditional Mexican spices on human health.

Effect of the smoking process and firewood type in the phytochemical content and antioxidant capacity of red Jalapeño pepper during its transformation to chipotle pepper

Chipotle pepper is a dry smoked red Jalapeño pepper well appreciated in the Mexican and American cuisines. Phytochemical content and antioxidant activity of red Jalapeño pepper has been previously reported, however, the effect of the smoking process in the content of phytochemicals, antioxidant capacity and capsaicinoids has not been previously reported. In the present study we found that the smoking process had a significant effect on the content of polyphenolic compounds and antioxidant capacity of red Jalapeño pepper. It induced a nearly 50% increase in total phenols and 15% increase in antioxidant capacity in chipotle pepper compared to fresh samples (in dry weight basis). Capsaicinoids and ascorbic acid content decreased in smoked samples, while carotenoids remained practically unchanged. The strongest effect of smoking was observed in the content of total flavonoids and catechin determined by HPLC. Therefore we can conclude that smoking process has a positive effect in the fruit because it raises its phytochemical properties. The type of wood used in the smoking process also had an effect on the phytochemical content and antioxidant capacity with traditional pecan wood being the best.