Processo de desidratação da alga Gracilaria birdiae beneficiada em laboratório e artesanalmente: análise da atividade antioxidante e composição centesimal

The main aim of this study was to compare the procedure for dehydration of Gracilaria birdiae prepared handmade and laboratory, collected in the northern coast of Rio Grande do Norte. The sample was collected in the Rio do Fogo beach in march 2009. The sample collected followed by two processing, the first the material prepared in laboratory was air-dried at 50°C for 24 hours in air-flow oven. The second the handmade sample was air-dried on the sun during three days. The extract was prepared in three different solvents: ethanol, hydroethanol and water, resulting in ethanol, hidroethanol and aqueous extracts from handmade and laboratory sample. In according with results only the ethanol extract was fractionated yielding the fractions hexane, dichloromethane and ethyl acetate fractions. The different process to obtain Gracilaria birdiae resulted in the samples with different shades. The soluble solids content was higher in the laboratory sample. The chemical composition the both samples were characterized by presenting a considerable amounts of carbohydrates, with amior percentage protein and ash, respectively, in the handmade and laboratory sample. In two samples showed a low content of lipids and the lipid profile showed a higher proportion of monounsaturated fatty acids, with the absence polyunsaturated handmade sample. The phytochemical screening by chemical reactions showed the presence of flavonoids, tannins, alkaloids and saponins the laboratory sample, presenting a greater diversity of bioactive compounds. Through of the analysis by thin layer chromatography was possible to identify the phytosterols β-sitosterol and stigmasterol the both samples, also suggest the presence of β-carotene and chlorophyll α the laboratory sample. The levels of total phenolics and flavonoids were more significant in the ethanol extract of the laboratory sample. The in vitro lethality showed that extracts of the laboratory sample and handmade from 125 to 500 μg/ mL, respectively, were highly lethal. In the evaluation of antioxidant capacity by the system β-carotene/ácido linoleic method and by DPPH radical scavernging assay, the ethanol extract from the laboratory process showed significantly greater activity than the other extracts, being and the first and second methods, respectively, lower and equivalent to the synthetic antioxidant BHT. The handmade ethanol extract has not demonstrated skill in deactivating free radicals, but showed activity in inhibiting lipid peroxidation, although the values were significantly lower than the laboratory sample. We conclude that the dehydration process in the laboratory is the most efficient technique to maintenance of the chemical composition present in the seaweed, providing beneficial properties such as antioxidant capacity. We emphasize that this property can be explored with the objective of adding commercial value to the final product, which will promote the expansion of production of this seaweed in the community of Rio do Fogo

Suco desidratado de caju (Anacardium occidentale L.) por atomização: caracterização físico-química, bioativa e estudo da vida de prateleira do produto

Despite the relatively organized cashew (Anacardium occidentale L.) productive chain and the number of cashew derivatives found in the market, it is estimated that over 90% of the cashew peduncle is wasted. A possible strategy for a better commercial exploitation of this agroindustrial commodity would be the production of spray dried cashew pulp. Thus, this paper approaches the yellow cashew pulp spray drying process and the final product evaluation. Based on that, the shelf life of the spray dried cashew pulp packed in different packaging was evaluated. Drying was conducted in two drying temperatures (140 °C to 150 °C) and two concentrations of Arabic gum (AG, 15% and 25%), which summed four experimental groups. The drying performance was evaluated as well as the physicochemical characteristics (moisture, water activity, total soluble solids, pH, density, solubility, particle diameter, hygroscopicity, degree of caking, color, scanning electronic microscopy and X-ray diffraction), composition (protein, ash, fat and sugars) and bioactive and functional value (total phenolic compounds, carotenoids, ascorbic acid and antioxidant activity) of the final products. Results showed spray drying efficiency higher than 65% for all experiments, mainly for the C4 group (150 °C and 25% AG) which reached efficiency of 93.4%. It was also observed high solubility (94.7% to 97.9%) and the groups with lower hygroscopicity (5.8% and 6.5%) were those with the highest proportion of drying coadjuvant. The particle diameters ranged between 14.7 μm and 30.2 μm and increased with the proportion of AG. When comparing the product before and after spray drying, the drying impact was evident. However, despite the observed losses, dried yellow cashew showed high phenolic concentration (from 235.9 to 380.4 mg GAE eq / 100 g DM), carotenoids between 0.22 and 0.49 mg/100 g DM and remarkable ascorbic acid levels (852.4 to 1346.2 mg/100 g DM), in addition to antioxidant activity ranging from 12.9 to 16.4 μmol TE/ g DM. The shelf life study revealed decreased phenolic content over time associated to a slight water activity increase. Overall, our results unveil the technological and bioactive potential of dried yellow cashew as a functional ingredient to be used in food formulations or as a ready-to-use product. The technological approach presented here can serve as an efficient strategy for a rational use of the cashew apple, avoiding its current underutilization

Análises físico-químicas de polpas de frutas e avaliação dos seus padrões de identidade e qualidade

The pulps are products that add economic value enjoy the fruits of the surplus productions of the same. Have good market acceptance because of its practicality and diversity of flavors available year round. In order to assess the quality of the fruit pulp through the physical and chemical parameters and the characteristics of manufacturing industry, we analyzed 36 samples of frozen fruit pulp of three brands marketed in RIO Grande do Norte, 14 brand A, 12 of 10 brand B and brand C, which corresponded to 14 different flavors, of which 10 have identity Standards and Quality (ISQ S) established by the Ministério da Agricultura, Pecuária e Abastecimento (MAPA), totaling 27 samples with ISQ s. We conducted the following physicalchemical analyzes on samples of fruit pulp: Total solids, total soluble solids, pH, titratable acidity, total sugars and the determination of ascorbic acid. The percentage of failure for each parameter evaluated was 37, 04% in total soluble solids, 22,22% for total solids and titratable acidity, 7,40% in relation to pH. The total sugars were within the requirements demanded by the MAPA and ascorbic acid content, determined only in the pulp of acerola and cashew, presented a non compliance in the pulp of brand B. The percentage of failures of the pulps with ISQ S was 59% with brand A, B and C accounted for 3,70%, 33,33% and 22,22% respectively. The pulps which have no established atandards such as pineapple pulp, showed similar values between brands and literature data unlike the pulp of plum, jackfruit and tamarind which diverged greatly in parameters such as total solids and total soluble solids. The study demonstrates the need for greater quality control by the producers with respect to raw materials, processing, packing, stored and the importance of ISQ S to establish the flavors have not yet covered by existing legislation, but already highly commercialized

Desidratação de polpas de frutas pelo método foam-mat

This study aimed to investigate the foam mat drying process of pineapple and mango pulp, as well as to evaluate the final product quality. Initially, the selection of fruit and additives was conducted based on density and stability determinations of mango, seriguela, umbu and pineapple foams. After selecting pineapple and mango for further studies, the fruit pulps and fruit foams were characterized in regard to their physicochemical composition. The temperature (60oC or 70oC) and the foam thickness (4 and 11 mm) were evaluated in accordance to the obtained drying curves and after model adjustment. Mango and pineapple powders obtained at the best process conditions were characterized in regard to their physicochemical composition, solubility, reconstitution time. Yoghurts were prepared with the addition of pineapple and mango powders and they were evaluated for their sensory acceptance. Results show that the best drying rates were achieved by using 70o C and layers 4mm thick for both fruits. The Page model successfully fitted the drying experimental data and it can be used as a predictive model. Pineapple and mango powders showed acid pH, high soluble solids content, low water activity (approx. 0.25), lipids between 1.46% and 2.03%, protein around 2.00%, and ascorbic acid content of 17,73 mg/100g and 14.32 mg/100g, for mango and pineapple, respectively. It was observed higher ascorbic acid retention for pineapple and mango powders processed at 70o C, which would be explained by the lower drying time applied. The fruit powders exhibited high solubility and fast reconstitution in water. The sensory acceptance indexes for yoghurts with the addition of both fruit powders were higher than 70%, which reflect the satisfactory product acceptance

Caracterização físico-química e química do fruto do juazeiro (Ziziphus joazeiro Mart) e avaliação da sua conservação por fermentação láctica

Considering the plant biodiversity in the Brazilian Northeast, whose components can be inserted into sustainable production systems, the jujube (Ziziphus joazeiro Mart.) emerges as to recovery of its fruit. The present study has as objective to characterize the fruit of the jujube under the physical, physicochemical and chemical approach and assess its conservation by spontaneous lactic fermentation under the influence of chloride, sodium, calcium and potassium. According to the legislation, vegetable acidified by fermentation that is subjected to lactic acid fermentation in order to achieve a final product pH less than or equal to 4.5. The results of the physical, chemical and physico-chemistry of ripe fruit jujube showed the potential of this species for agro-processing. The yield of edible portion (91.83%), soluble solids content (18,98º Brix), titratable acidity (0.14% citric acid), pH (5.30) and its composition, divided in moisture (79.01%), protein (2.01%), lipids (0.52%), carbohydrate (17.59%), fiber, ash (0.76%) and its minerals were consistent with the characteristic profile fruits, thus favoring the development of spontaneous lactic fermentation. The minimum pH and titratable acidity observed maximum in the fermentation process under the influence of mixtures of salts (NaCl and KCl NaCl2) values ranged from 3.4 to 3.7 and from 0.54 to 0.95 (% lactic acid), respectively. The profile of the lactic fermentation of fruit of jujube in brine, fermented microbiological quality and the result of analysis of primary sensory prepared preserved, the application of endorsed by the consumer sensory evaluation, more particularly, derived from fermented fruit preserved in the presence of chloride sodium, in accordance with the traditional techniques of lactic fermentation of vegetables. The results of sensory evaluation conducted with 100 consumers (tasters) revealed an acceptance rate equal to 78% of the preserve. Despite restrictions on the sensory acceptability of fermented under the influence of salts (KCl and CaCl2) substitutes sodium chloride, preserved these perspectives presented to balance the optimization of mixtures, health product safety and consumer awareness towards prefer a more healthy product with reduced sodium content.

Determinação de parâmetros (sólidos solúveis, pH e acidez titulável) em ameixas intactas usando espectroscopia no infravermelho próximo e seleção de comprimento de onda

The aim of this study was to evaluate the potential of near-infrared reflectance spectroscopy (NIRS) as a rapid and non-destructive method to determine the soluble solid content (SSC), pH and titratable acidity of intact plums. Samples of plum with a total solids content ranging from 5.7 to 15%, pH from 2.72 to 3.84 and titratable acidity from 0.88 a 3.6% were collected from supermarkets in Natal-Brazil, and NIR spectra were acquired in the 714 2500 nm range. A comparison of several multivariate calibration techniques with respect to several pre-processing data and variable selection algorithms, such as interval Partial Least Squares (iPLS), genetic algorithm (GA), successive projections algorithm (SPA) and ordered predictors selection (OPS), was performed. Validation models for SSC, pH and titratable acidity had a coefficient of correlation (R) of 0.95 0.90 and 0.80, as well as a root mean square error of prediction (RMSEP) of 0.45ºBrix, 0.07 and 0.40%, respectively. From these results, it can be concluded that NIR spectroscopy can be used as a non-destructive alternative for measuring the SSC, pH and titratable acidity in plums

Use of Fibres Obtained from the Cashew (Anacardium ocidentale, L) and Guava (Psidium guayava) Fruits for Enrichment of Food Products

OLIVEIRA, E. L. et al. Use of Fibres obtained from the Cashew (Anacardium ocidentale, L) and Guava (Psidium guayava) Fruits for Enrichment of Food Products. Brazilian Archives of Biology and Technology, Curitiba, PR, v. 48, p. 143-150, 2005.

Variação no conteúdo protéico e pigmentar em variantes cromáticas de Gracilaria domingensis nas populações naturais de Rio do Fogo-RN, BRASIL

The seaweed Gracilaria domingensis is a common species in the coast of Rio Grande do Norte. This species lives in the intertidal zone, where colour strains (red, green and brown) co-occur during the whole year. Seaweeds that live in this region are exposed to daily changes and to the rhythm of the tide. During the low tide they are exposed to dissection, hiper-or hipo-osmotic shock, high temperatures and high irradiance. The aim of this study was to analyze whether the pigment and protein content of the colour strains of G. domingensis is affected by some environmental parameters in a temporal scale. The seaweeds were collected during 10 months in the seashore of Rio do Fogo (RN). The total soluble proteins and the phycobiliprotein were extracted in phosphate buffer and the carotenoids were analyzed by a standardized method through HPLC-UV. The pigments analysis showed that phycoerithrin is the most abundant pigment in the three strains. This pigment was strongly correlated with nitrogen and the photosynthetically active radiation. Chlorophyll presented higher concentrations than carotenoids during the whole, but the ratio carotenoid/chlorophyll-a was modified by incident radiation. The most abundant carotenoid was ß-carotene and zeaxanthin, which had higher concentrations in the higher radiation months. The concentration increase of zeaxanthin in this period indicated a photoprotective response of the seaweed. The three strains presented a pigment profile that indicates different radiation tolerance profile. Our results pointed that the green strain is better adapted to high irradiance levels than the red and brown strains

Caracterização físico-química, reológica e sensorial de iogurte obtido pela mistura dos leites bubalino e caprino

Milk from different animals can be used for dairy production. Yoghurt is a popular fermented milk product and considered to be one of the greatest importance in terms of consumer acceptance and consumption. The present research deals with the production of strawberry set-type yoghurt by mixing goat and buffalo s milk and it has the objective of taking advantage of the intrinsic characteristics of each milk to produce a final product with desirable attributes. It was conducted by analyzing five experimental groups with different proportions of goat and buffalo s milk: C 100% goat s milk; 7C3B - 70% goat s milk and 30% buffalo s milk, 5C5B - 50% goat s milk and 50% buffalo s milk, 3C7B 30% goat s milk and 70% buffalo s milk; B - 100% buffalo s milk. Each group was evaluated for total solids content and the acidification profile was monitored every 30 minutes by pH analysis. The yoghurt samples were analyzed for physical-chemical (pH, acidity, protein, fat, total and reducing sugars, ash and total solids), rheological (syneresis and viscosity) and sensory characteristics (appearance, odor, consistency and flavour). Samples with higher percentual of bubaline milk reached Vm faster, but the time necessary for pH 4.6 (Te) were similar between groups. Statistical differences (p<0.05) were observed for fat and total solids content of yoghurt, with superior values for groups higher proportions of buffalo s milk. The parameters of behavior reached by the model of Ostwald of Waale pointed yoghurt samples as non-Newtonian and pseudoplastic fluids. Yoghurt made only with goat s milk (C) had higher values (p<0.05) for syneresis, which can be explained by its fragile coagulum. Additionally, this group also had the lowest sensory scores for the attributes consistence and taste, while bubaline yoghurt (B) obtained the best acceptance indexes for all of the appraised parameters

Análise da adição de resíduo oriundo do tratamento de esgotos em massa cerâmica utilizada para fabricação de telhas

Sludge of Wastewater Treatment Plants (WTPs) disposal is a problem for any municipality, for this reason the amount of sludge production is now a key issue in selecting treatment methods. It is necessary to investigate new applications for this waste type, due to the restrictions imposed by the environmental organs. The raw materials used in the Red Ceramic, are generally very heterogeneous, for this reason, such materials can tolerate the presence of different types of wastes. In Rio Grande do Norte, the roof tiles production corresponds to 60,61% from the total of ceramic units produced. Due to the importance of the ceramic industry of roof tiles for the state, allied to the environmental problem of the sludge disposal, this work had for objective to verify the possibility of the incorporation of sewage sludge in ceramic body used for production of roof tiles. In the research, sludge originating from drying beds of WTP of the Central Campus from UFRN and clays originating from a ceramic industry from Goianinha/RN were used. The raw materials were characterized by techniques of: analysis of particles distribution by diffraction to laser; real density; consistence limits; chemical analysis by X-ray fluorescence; mineralogical analysis by X-ray diffraction; organic matter; and solids content. Five batches of roof tiles were manufactured in the approximate dosages of 2%, 4%, 6%, 8% and 10%. To evaluate the properties of each final product, tests of water absorption, impermeability, bending strength, leachability and solubility were accomplished. The roof tiles manufactured with sludge presented characteristics similar to the roof tiles without sludge in relation to the environmental risk. The results showed that it is possible to use approximately up to 4% of sludge in ceramic bodies for production of roof tiles. However, it is observed that the high amount of organic matter (71%) present in the sludge is shown as factor that limits the sludge incorporation in ceramic bodies, worsening the quality of the roof tiles. It is necessary the use of mixtures of different raw materials under point of view of the granulometry and of the other chemical and mineralogical properties for the obtaining of a satisfactory mass to the production of ceramic roof tiles

Caracterização do conteúdo de fossas e tanques sépticos na cidade de Natal

Only 32% of the population of Natal is attended by sewage, while the remaining population use pits and septic tanks. The characterization of the contents of septic tanks and pits contributes to the performance of such system and may guide the decision on treatment of these contents. The main of this research is to characterize the contents of interior residential pits and septic tanks in the greater Natal, with the following specific goals: to develop and manufacture a sampler capable of collecting a representative sample of the entire column (the surface scum, the clarified liquid and sludge bottom); to compare the contents of the tanks with the pits; to compare the contents of the septage from vacuum trucks; to relate the composition content with socioeconomic characteristics of households; to compare the content in both chambers of the septic tanks in series; to assess the situation of the content before and six months after the cleanness; and ultimately propose a pilot scale plant for treatment of septage. Once the sampler was developed, samples were collected within 14 septic tanks and 10 pits in many districts of Natal. Medians of the 24 systems were obtained: temperature, pH, conductivity, oil and grease, total solids, total suspended solids and sediments of 28.0 °C, 6.95; 882 mS/cm, 75.2 mg/L; 10,169 mg/L, 6,509 mg/L and 175 mL/L respectively; 111.0 mgN/L for ammonia, 130.5 mgN/ L for organic nitrogen, 0.2 mgN/L for nitrite, 0.4 mg/L for nitrate; 8935 mgO2/L for COD, 29.2 mgP/L for total phosphorus, thermotolerant coliforms from 9.95 E +06 CFU/100mL helminth eggs and 9.2 eggs/L with a maximum concentration of 688 eggs/L and minimum of 0 eggs/L. Medians of organic nitrogen and TKN were significantly different between groups of tanks and pits. The systems with cleanness gap from 11 and 20 years presented the higher concentrations for most variables. The effluent from the toilets and bathrooms participate more effectively in contributing fractions of solids, alkalinity, nitrogen, COD, total phosphorus, thermotolerant coliforms and helminth eggs. The systems used by socioeconomics class with income from R$ 3,700.00 to R$ 7,600.00, presented higher concentrations for COD, nitrogen, solids and helminth eggs. The first of the two chambers had always presented higher concentrations over the second compartment. The analysis of variance for most variables, showed that the values of septic tanks, pits and septage from vacuum trucks belong to the same group. In the samples taken after cleanness, the median of pH and temperature increased, while alkalinity, COD, organic nitrogen, total phosphorus, ammonia and helminth eggs decreased. The oils and greases and thermotolerant coliforms had slightly varied due to the continuous release of sewage into the systems that maintained their steady state concentrations.

Use of Fibres Obtained from the Cashew (Anacardium ocidentale, L) and Guava (Psidium guayava) Fruits for Enrichment of Food Products

OLIVEIRA, E. L. et al. Use of Fibres obtained from the Cashew (Anacardium ocidentale, L) and Guava (Psidium guayava) Fruits for Enrichment of Food Products. Brazilian Archives of Biology and Technology, Curitiba, PR, v. 48, p. 143-150, 2005.

Variação no conteúdo protéico e pigmentar em variantes cromáticas de Gracilaria domingensis nas populações naturais de Rio do Fogo-RN, BRASIL

The seaweed Gracilaria domingensis is a common species in the coast of Rio Grande do Norte. This species lives in the intertidal zone, where colour strains (red, green and brown) co-occur during the whole year. Seaweeds that live in this region are exposed to daily changes and to the rhythm of the tide. During the low tide they are exposed to dissection, hiper-or hipo-osmotic shock, high temperatures and high irradiance. The aim of this study was to analyze whether the pigment and protein content of the colour strains of G. domingensis is affected by some environmental parameters in a temporal scale. The seaweeds were collected during 10 months in the seashore of Rio do Fogo (RN). The total soluble proteins and the phycobiliprotein were extracted in phosphate buffer and the carotenoids were analyzed by a standardized method through HPLC-UV. The pigments analysis showed that phycoerithrin is the most abundant pigment in the three strains. This pigment was strongly correlated with nitrogen and the photosynthetically active radiation. Chlorophyll presented higher concentrations than carotenoids during the whole, but the ratio carotenoid/chlorophyll-a was modified by incident radiation. The most abundant carotenoid was ß-carotene and zeaxanthin, which had higher concentrations in the higher radiation months. The concentration increase of zeaxanthin in this period indicated a photoprotective response of the seaweed. The three strains presented a pigment profile that indicates different radiation tolerance profile. Our results pointed that the green strain is better adapted to high irradiance levels than the red and brown strains

Mobilização de reservas e partição de metabólitos durante a germinação da semente e o estabelecimento da plântula em moringa

Seed germination and seedling establishment are critical processes for commercial plantation and depend directly on reserve mobilization as a source of cellular fuels and biosynthetic precursors. In this way, we investigated the coordination among reserve mobilization, metabolite partitioning, and mobilizing enzyme activities in Moringa oleifera Lam (moringa) an oil-seeded species employed in biofuel production. Seeds were germinated under controlled conditions and seedlings were grown hydroponically at a greenhouse. Samples were harvested at 0, 4, 8, 10, 12, 16, and 20 days after imbibition (DAI). The contents of dry mass (DM), neutral lipids (NL), soluble proteins (SP), starch, total soluble sugars (TSS), non-reducing sugars (NRS), and total free amino acids (TFAA) as the activity of isocitrate lyase (ICL), acid proteases, and amylases were determined. The mobilization of storage proteins was initiated during seed germination whereas the mobilization of storage lipids and starch was triggered throughout seedling establishment although all reserves have been depleted until 20 DAI. The partitioning of DM and metabolites to the roots and the shoots was uneven during seedling establishment. Low shoot/root ratio on the basis of DM could be related to the natural occurrence of moringa in drought climates. In the roots, TSS, NRS, and TFAA were accumulated from 12 to 16 DAI and then were consumed until the end of the experiment. In the shoots, TSS and TFAA were consumed in parallel with NRS accumulation from 12 to 20 DAI. The activity of ICL, acid proteases, and amylases was coordinated with the mobilization of lipids, proteins and starch respectively. Thus, we propose that the patterns of reserve mobilization and metabolite partitioning verified in moringa seem distinct from those found to other tree species and may be involved in metabolic strategies to enable environment colonization

Reaproveitamento e caracterização dos resíduos orgânicos provenientes do Programa MESA DA SOLIDARIEDADE da CEASA/RN

As an auxiliary tool to combat hunger by decreasing the waste of food and contributing for improvement of life quality on the population, CEASA/RN has released from August/03 to August/05 the program MESA DA SOLIDARIEDADE. Despite of the positive results of this program, that has already distributed around 226 tons of food, there is still food being thrown in the trash as the deliver of the same food in its natural form would be a health risk to those who would consume it and only the correct processing of this food can make it edible. This work has as a goal the reuse of solid residues of vegetal origin generated by the CEASA/RN, through the Program MESA DA SOLIDARIEDADE and the characterization of the product obtained so it might be used as a mineral complement in the human diet. To the collecting of samples (from September until December /2004) it was developed a methodology having as a reference the daily needs of mineral salts for infants at the age of seven to ten. The sample was packed in plastic bags and transported in an ambient temperature to the laboratory where it was selected, weighted, disinfected, fractionated and dried to 70ºC in greenhouse. The dry sample was shredded and stored in bottles previously sterilized. The sample in nature was weighted in the same proportion of the dry sample and it was obtained a uniform mass in a domestic processor. The physical-chemical analyses were carried out in triplicate in the samples in nature and in the dry product, being analyzed: pH, humidity, acidity and soluble solids according to IAL (1985), mineral salts contents (Ca, K, Na, Mg, P and Fe) determined by spectrophotometry of Atomic Absorption, caloric power through a calorimetric bomb and presence of fecal traces and E. coli through the colilert method (APHA, 1995). During this period the dry food a base of vegetables presented on average 5,06% of humidity, 4,62 of pH, acidity of 2,73 mg of citric acid /100g of sample, 51,45ºBrix of soluble solids, 2.323,50mg of K/100g, 299,06mg of Ca/100g, 293mg of Na/100g, 154,66mg of Mg/100g, 269,62mg of P/100g, 6,38mg of Fe/100g, caloric power of 3,691Kcal/g (15,502KJ/g) and is free of contamination by fecal traces and E..coli. The dry food developed in this research presented satisfactory characteristics regarding to its conservation, possessing low calories, constituting itself a good source of potassium, magnesium, sodium and iron that can be utilized as a food complement of these minerals