Manuel Olalla

Mineral content in legumes and nuts: contribution to the Spanish dietary intake

We evaluated the levels of essential elements as Cu, Cr, Fe and Zn, and toxic elements as Al, Ni, Pb and Cd in a total of 40 samples of different legumes and 56 samples of different nuts, that are widely consumed in Spain. These elements were determined in the samples mineralized with HNO(3) and V(2)O(5), using electrothermal atomic absorption spectrometry (ETAAS) as the analytical technique. Reliability of the procedure was checked by analysis of a certified reference material. No matrix effects were observed and aqueous standard solutions were used for calibration. In legumes, the levels ranged from 1.5-5.0 microg Cu/g, 0.05-0.60 microg Cr/g, 18.8-82.4 microg Fe/g, 32.6-70.2 microg Zn/g, 2.7-45.8 microg Al/g, 0.02-0.35 microg Ni/g, 0.32-0.70 microg Pb/g and not detectable-0.018 microg Cd/g. In nuts, the levels ranged from 4.0-25.6 microg Cu/g, 0.25-1.05 microg Cr/g, 7.3-75.6 microg Fe/g, 25.6-69.0 microg Zn/g, 1.2-20.1 microg Al/g, 0.10-0.64 microg Ni/g, 0.14-0.39 microg Pb/g, and not detectable-0.018 microg Cd/g. A direct statistical correlation between Cu-Cr, Zn-Al and Cr-Ni (P<0.05), and Al-Pb (P<0.001), has been found. The growing popularity of these products in recent years on the basis of its nutritional properties and beneficial effects, requires additional data and a periodical control. In addition, the present findings are of potential use to food composition tables.

Milk Protein Peptides With Angiotensin I-Converting Enzyme Inhibitory (ACEI) Activity

Bioactive peptides derived from milk proteins are currently of great scientific interest due to their beneficial health properties. The group of bioactive peptides most studied up until now are the angiotensin-I converting enzyme inhibitory (ACEI) peptides, which, when administered orally, seem to possess the capacity to lower blood pressure in hypertensive subjects. The various techniques of separation, identification, and classification of bioactive peptides obtained from milk and milk products, permit the selection of molecules with the highest level of health benefits to be used as a functional ingredient in the production of milk products with blood pressure-lowering effects such as Evolus® or Calpis®. This review focuses on the major research in the areas of isolation, identification, and application of bioactive peptides with ACEI activity in milk proteins, paying special attention to in vitro, in animal model systems, and in clinical studies of hypertensive patients.

Standardisation of the chromatic characteristics of sobretablas wine macerates obtained by an accelerated ageing technique using heating and oak shavings

Abstract This paper presents the results of the selection and chromatic characterisation of macerates obtained from sobretablas wines and oak shavings, aged according to the method proposed and studied by our research group. This method allows considerable shortening of the time spent in barrels and represents a viable alternative to the oxidative ageing of oloroso wines from the “Jerez-Sherry” Origin Appellation (Spain). A detailed study was undertaken of the influence on chromatic characteristics of such factors as heating, maceration and exhaustion of the shavings (using water and hydroalcoholic mixtures). By using caramel colouring additive (authorised in the European Union as E-150), colour values entirely equivalent to those of commercial wines are achieved, which are not even apparent under sensorial analysis.

Levels of Se, Zn, Mg and Ca in commercial goat and cow milk fermented products: Relationship with their chemical composition and probiotic starter culture

We determined Se, Zn, Mg and Ca levels in 42 samples of goat and cow fermented milks which are widely consumed in Spain were determined. Atomic absorption spectrometry (hydride generation for Se and flame atomisation for remaining elements) was used as an analytical technique. Reliability of the procedure was checked. Only Mg levels in goat fermented milks were significantly higher to those found in cow fermented milks (p<0.022). Important similarities in concentrations and behaviours for Mg and Ca have been observed. Mg contents were significantly correlated with Zn (r=0.590; p<0.001) and Ca (r=0.344; p<0.028) concentrations, Zn, Mg and Ca levels with protein content (r=0.554, r=0.479, r=0.388, respectively), Mg levels with fats (r=0.403; p=0.011) and Se levels with carbohydrates (r=-0.379; p=0.031). Mineral and macronutrient levels in yogurts with traditional probiotic starter cultures were not significantly different to those found in fermented milks with additional probiotic microorganisms (p>0.05). It was concluded that goat fermented milks are a better source for Mg than cow samples.

Copper, zinc, calcium and magnesium content of alcoholic beverages and by-products from Spain: Nutritional supply

Levels of copper, zinc, calcium and magnesium were measured in alcoholic beverages (whiskies, gins, rums, liquors, brandies, wines and beers) and by-products (non-alcoholic liquors and vinegars) using flame atomic absorption spectrometry (FAAS). Mineral concentrations were found to be significantly different between the nine alcoholic and non-alcoholic by-products studied (p < 0.001). In distilled alcoholic beverages, concentrations measured in rums and brandies were statistically lower than those determined in gins and alcoholic liquors (p = 0.001). For Cu, measured concentrations were statistically different for each of the five groups of distilled alcoholic beverages studied (p < 0.001). In fermented beverages, Zn, Ca and Mg levels were significantly higher than those concentrations determined in distilled drinks (p < 0.005). Contrarily, Cu concentrations were statistically lower (p < 0.001). Wines designated as sherry had significantly higher Ca and Mg levels (p < 0.005). White wines had significantly higher Ca and Zn levels (p < 0.05) compared with red wines and, contrarily, Cu concentrations were significantly lower (p < 0.005). In wine samples and corresponding by-products (brandy and vinegar), statistical differences were established for all minerals analysed (p < 0.01). Remarkably, for Cu, the concentrations determined in brandies were statistically higher. On the basis of element levels and the official data on consumption of alcoholic beverages and by-products in Spain, their contribution to the daily dietary intake (DDI) was calculated to be 124.6 µg Cu day−1 and 193.3 µg Zn day−1, 40.3 mg Ca day−1 and 19.9 mg Mg day−1. From all studied elements, Cu was the one for which alcoholic beverages constitute a significant source (more than 10% of recommended daily intake). These findings are of potential use to food composition tables.

Assessing the bioavailability of polyphenols and antioxidant properties of extra virgin argan oil by simulated digestion and Caco-2 cell assays. Comparative study with extra virgin olive oil

Argan oil is becoming increasingly popular in the edible-oil market as a luxury food with healthy properties. This paper analyzes (i) the bioavailability of the polyphenol content and antioxidant properties of extra virgin argan oil (EVA) by the combination of in vitro digestion and absorption across Caco-2 cells and (ii) the protective role of the oil bioaccessible fraction (BF) against induced oxidative stress. Results were compared with those obtained with extra virgin olive oil (EVO). Higher values of polyphenols and antioxidant activity were observed in the BF obtained after the in vitro digestion of oils compared with the initial chemical extracts; the increase was higher for EVA but absolute BF values were lower than EVO. Bioaccessible polyphenols from EVA were absorbed by Caco-2 cells in higher proportions than from EVO, and minor differences were observed for antioxidant activity. Preincubation of cell cultures with BF from both oils significantly protected against oxidation, limiting cell damage and reducing reactive oxygen species generation.

The Probiotic Bacterial Strain Lactobacillus fermentum D3 Increases In Vitro the Bioavailability of Ca, P, and Zn in Fermented Goat Milk

We determined calcium, magnesium, phosphorus and zinc levels in a total of 27 samples of commercial goat- and cow-milk fermented products and 9 samples of a goat-milk fermented product with addition of a probiotic bacterial strain, Lactobacillus fermentum D3, manufactured experimentally by our research group. Atomic absorption spectroscopy with flame atomization and UV/VIS spectrophotometry were used as analytic techniques. The results of an in vitro digestion process showed that the bioavailability of calcium, phosphorus, and zinc was significantly higher in our fermented milk containing the probiotic bacterial strain than it was in commercial goat-milk fermented products. Furthermore, our product showed a significantly higher bioavailability of calcium and zinc compared to goat- and cow-milk fermented products made with other microorganisms. We conclude that, in in vitro assays, strain D3 seems to increase the bioavailability of these minerals and that this new product may constitute a better source of bioavailable minerals compared to other products already on the market.

Characterization of Fatty Acid Profile of Argan Oil and Other Edible Vegetable Oils by Gas Chromatography and Discriminant Analysis

Virgin argan oil is an emergent oil that is being introduced into specialized international markets as a healthy and luxury food. In order to compare the fatty acid composition of argan oil with that of the eleven other vegetable edible oils, a combination of gas chromatography as analytical technique and multivariate discriminant analysis was applied. This analysis takes into account the conjoint effect of all the variables analyzed in the discrimination between oils and also shows the contribution of each variable to oils characterization. The model correctly classified 100% oil samples. According to the fatty acid composition, argan oil showed closest similarity firstly with sesame oil and secondly with high oleic sunflower oil. Olive oil was close to avocado oil and almond oil, followed by argan oil. Thus, similarities and differences between vegetable oils based on their fatty acid profile were established by the application of multivariate discriminant analysis. This method was proven to be a useful tool to study the relationships between oils according to the fat composition and to determine the importance of the fatty acid variables on the oils classification.

Ascorbic acid in diet supplements: loss in the manufacturing process and storage.

The ascorbic acid content was determined in 25 different diet supplements commercially available to the consumer in two pharmaceutical forms (pills and ampoules). These products are widely consumed by several population groups (elderly people, sportsmen, adolescents, children, etc.). High-performance liquid chromatography was used as the analytical technique. The proposed method has been validated with good linearity, reproducibility, recovery and accuracy, and can be used in routine analyses and in quality control. The ascorbic acid content in pills ranged from 15.62 to 50.16 mg/g, and in that ampoules from 2.12 to 8.83 mg/ml. Depending on the dosage rates, these levels would represent approximately 20-50% of the daily dietary intake recommended by the National Research Council. Possible losses in the manufacturing process and stability during storage for 30 days at 40 ± 2°C without light, were tested. In relation to the ascorbic acid concentrations stated on the labels, a loss of 12.0-21.9% in pills and of 11.7-18.0% in ampoules was detected. In relation to the stability conditions, the losses are of 1.8-24.8% in pills and of 10.4-19.3% in ampoules. The pasteurisation and sterilisation processes produced a mean loss of ascorbic acid in ampoules of 2.1 and 1.4%, respectively. A statistically significant direct correlation was observed between ascorbic acid loss and content in proteins, humidity, ash, and fructose. The influence of the pharmaceutical form was also tested. Data revealed that the control of losses during the manufacturing and commercialisation process of these products is necessary to ensure the intake of vitamin C from these products by the consumer.

Ultrafiltration of skimmed goat milk increases its nutritional value by concentrating nonfat solids such as proteins, Ca, P, Mg, and Zn

Goat milk has been reported to possess good nutritional and health-promoting properties. Usually, it must be concentrated before fermented products can be obtained. The aim of this study was to compare physicochemical and nutritional variables among raw (RM), skimmed (SM), and ultrafiltration-concentrated skimmed (UFM) goat milk. The density, acidity, ash, protein, casein, whey protein, Ca, P, Mg, and Zn values were significantly higher in UFM than in RM or SM. Dry extract and fat levels were significantly higher in UFM than in SM, and Mg content was significantly higher in UFM than in RM. Ultrafiltration also increased the solubility of Ca and Mg, changing their distribution in the milk. The higher concentrations of minerals and proteins, especially caseins, increase the nutritional value of UFM, which may therefore be more appropriate for goat milk yogurt manufacturing in comparison to RM or SM.