Belén García-Villanova

Phytic acid content in milled cereal products and breads

Abstract Phytic acid was determined in cereal (brans, flours and milled wheat-products) and breads. The method was based on complexometric titration of residual iron (III) after phytic acid precipitation. The cereal flours showed values ranged between 3–4 mg/g for soft wheats, 9 mg/g for hard wheat and 22 mg/g for whole wheat. Corn, millet and sorghum flours reported a mean of 10 mg/g and oat, rice, rye and barley between 4 and 7 mg/g. Wheat brans had wide ranges (25–58 mg/g). The phytic acid for oat brans was half that of wheat bran (20 mg/g) and higher value (58 mg/g) than that for rice bran. The milling products (semolinas) from hard wheat exhibited 10 mg/g and soft wheat a mean of 23 mg/g. The breads made with single or mixture cereal flours exhibited ranges between 1.5 and 7.5 mg/g. The loss of phytic acid relative to unprocessed flours was between 20% for oat bread and 50% for white bread.

Hydroxymethylfurfural and methylfurfural content of selected bakery products

Abstract Hydroxymethylfurfural (HMF), methylfurfural (MF) and colour (100- L *) were determined in nine common varieties of selected bakery products from Spain. Identical sample preparation and HPLC conditions were used to determine HMF in all bakery products. Recovery of HMF was 93.3%. The HMF values ranged from 4.1 to 151.2 mg/kg. The colour index (100- L *) ranged from 23.1 to 42.9. No linear correlation was found between HMF and colour. MF was determined by gas-liquid chromatography. The precision was 12%. The MF values ranged from 1.6 to 11.5 mg/kg. Fried products showed higher values than baked products. Linear correlation was obtained ( r 2 =0.875) between HMF and MF for baked products.

Determination of Furan Precursors and Some Thermal Damage Markers in Baby Foods: Ascorbic Acid, Dehydroascorbic Acid, Hydroxymethylfurfural and Furfural

The presence of ascorbic acid (AA), vitamin C (AA + dehydroascorbic acid (DHAA)) and furfural as potential precursors of furan in commercial fruit and vegetable jarred baby food was studied. Hydroxymethylfurfural (HMF) was also determined and used, together with furfural levels, as markers of thermal damage. AA, calculated DHAA and vitamin C values ranged between 22.4 and 103, 2.9 and 13.8, and 32.1 and 113.2 mg/100 g, respectively, in fruit-based baby food. However, no trace of AA was found in the vegetable-based baby food samples tested, probably because these samples are not enriched in vitamin C and the content of this vitamin in fresh vegetables is destroyed during processing. Furfural values ranged from not detected to 236 microg/100 g, being higher in vegetable samples than in fruit samples possibly because of greater AA degradation favored by a higher pH in the vegetable samples. HMF values (range: not detected-959 microg/100 g), however, were higher in the fruit samples, probably due to greater carbohydrate content degradation and as a consequence of the Maillard reaction, favored by a lower pH in these samples. According to these results, HMF would be the optimum indicator of thermal treatment for fruits, and furfural for vegetables. The higher furfural content of vegetable baby food could be considered an index of greater AA degradation and, therefore, the furan content might be higher in this kind of sample than in fruit-based baby food.

Determination of hydroxymethylfurfural in baby cereals by high performance liquid chromatography

Abstract A liquid chromatography method for the detection and quantification of 5-hydroxymethyl-2-furaldehyde (HMF) in baby cereals is described. HMF was obtained by centrifugation and the supernatant was clarified by the addition of Carrez solution. The mixture was centrifuged for 5 min at 5,000 rpm. The samples were analysed on a reverse-phase C18 column and ultraviolet detector (284 nm) in isocratic elution with 95:5 water-acetonitrile. Average recovery of HMF by the standard addition method was 96.9%. The variation coefficients for three levels of concentration, (3.24, 22.82 and 65.50 ppm) were 2.40. 2.14 and 1.09% respectively. Limit of detection was ≥0.09 ppm. This method was applied by determination of HMF in commercial baby cereals.

Blockage of available lysine at different stages of infant cereal production

Determination of available lysine was used to assess the heat damage produced during the processing of cereals for infant foods. The infant cereals analysed were: wheat, 7 and 8 cereals, rice, rice-corn, rice-corn-soy and oat. Lysine losses during the toasting of flours ranged between 14 and 29%. Roller-drying treatment caused considerable heat damage, with a 53% decrease of available lysine in roller-dried rice-corn-soy. However, oat flour was less susceptible, with a 5% reduction in available lysine during roller-drying. # 1999 Society of Chemical Industry

Influence of technological processes on phenolic compounds, organic acids, furanic derivatives, and antioxidant activity of whole-lemon powder

The healthy properties of citrus fruits have been attributed to ascorbic acid and phenolic compounds, mainly to flavonoids. Flavonoids are important phytonutrients because they have a wide range of biological effects that provide health-related properties. In this context, this study seeks to characterise the phenolic compounds in lemon and their stability in different drying processes (freeze-drying and vacuum-drying) and storage conditions (-18 and 50°C for 1 and 3months). A powerful high-performance liquid chromatography coupled to DAD and electrospray-ionization time-of-flight mass spectrometry (HPLC-ESI-TOF-MS) method has been applied for the separation, identification, and quantification of 19 phenolic compounds and 4 organic acids. To our knowledge, two hydroxycinnamic acids have been identified for the first time in lemon. Folin-Ciocalteu was applied to determine total phenolic compounds and TEAC, FRAP, and ORAC were applied to determine the antioxidant capacity of lemon. Total phenolic content significantly differed in the samples analysed, vacuum-dried lemon showing the highest phenolic content, followed by freeze-dried lemon and, finally, vacuum-dried lemon stored at 50°C for 1 and 3months. The content in furanic compounds was determined to evaluate the heat damage in lemon and it was showed an increase with the thermal treatment because of the triggering of Maillard reaction. As exception of ORAC, antioxidant-capacity assays were not correlated to phenolic content by HPLC due to the formation of antioxidant compounds during Maillard reaction.

DETERMINATION OF FURFURAL COMPOUNDS IN ENTERAL FORMULA

HPLC methods are described for the determination of furanic compounds (hydroxymethylfurfural and furfural) in enteral formulas prepared with dextrinomaltose and milk proteins, and in model systems enclosing these ingredients. These compounds were extracted in aqueous solution, purified with organic solvents, and separated in a reversed-phase C18 column with water-acetonitrile (95:5 v/v). Average recovery rates of HMF and furfural were 99.2% and 71.1%, respectively. The variation coefficients for HMF and furfural were 2.41% and 1.23%, respectively. The detection limit was 0.01 mg/L for both compounds. HMF and furfural levels in enteral formulas ranged from 0.05 to 19.1 mg/L and from 0.14 to 0.72 mg/L, respectively.

Changes in sugar profile during infant cereal manufacture

Abstract A sugar profile study of wheat-based, rice-based and oats infant cereals was conducted to determine changes produced during processing. Two extraction procedures were assayed. The fructose, glucose, sucrose, maltose, maltotriose, isomaltotriose and raffinose contents of the cereals were analysed by gas liquid chromatography. In untreated flours, sucrose was the main sugar; glucose, fructose, maltose and raffinose were also detected. During hydrolysis, there were increases in the maltose (2.1–7.6 g/100 g, depending on the sample), glucose and fructose contents and maltotriose and isomaltotriose were also increased. Roller-drying reduced the maltose content. Four commercial samples with rice or wheat were analysed: the sugar composition was 20 g/100 g sucrose and 3 g/100 g maltose. Other ingredients in the formulations were also analysed.

Description of indexes based on the adherence to the Mediterranean Dietary Pattern: a review

INTRODUCTION diet quality indexes are tools are aimed at quantifying the compliance to a defined dietary pattern. These indexes are a combined measure of dietary factors (food groups, foods, nutrients and ratios) and/ or lifestyles factors. The Mediterranean Diet (MD) is a dietary pattern characterized by their positive effects against chronic diseases. There have been many indexes proposed for the assessment of this dietary pattern. An evaluation of their composition and health benefits is therefore convenient. OBJECTIVE the objective is to evaluate indexes of adherence to the MD with regard to their definition, methodological issues and validation as reported in epidemiological studies. METHODS we searched in PubMed for studies that developed MD Indexes up to October 2014. RESULTS a total number of 22 indexes were identified, with differences regarding the number of components (7-28), scoring (0, 1, 2, 3, 4, 5, 8 or 10, in case of compliance), range (0-100) and type of components (which could be food groups/foods or their combination, with nutrients). Among the positive components, fruits and vegetables were the most common and meats, among the negative components. There were also differences with regard to their composition and evaluation (e.g. criteria of moderate alcohol consumption), as well as with the scoring system (in medians, terciles or established servings). CONCLUSIONS this review suggests that since there is great heterogeneity in the definition of MD. It would be therefore convenient to establish more clearly the components to be included and to establish commonly defined criteria to quantify this dietary pattern.

Evolution of Fatty Acid Profile and Lipid Oxidation During Enteral Formula Storage

BACKGROUND Enteral formulas can be stored for up to 2 years. Fat oxidation during storage can lead to the loss of nutritive value and generation of toxic products such as lipid peroxides. METHODS Two standard enteral formulas were stored for short periods at high temperatures (1-4 weeks at 32-55°C) or for long periods at low temperatures (12-36 weeks at 4°C, 20°C, or 30°C). The present study included the assessment of lipid oxidation by measuring related fluorescent compounds and the evolution of fatty acids profile. RESULTS Enteral formula fat was oxidized under all assayed conditions, including storage at 4°C. The loss of essential fatty acids (linoleic and linolenic acids) was always higher when time and temperature were increased. The ω6/ω3 ratio was increased by storage from 5.6 to 7.8, which could exacerbate the inflammatory response in critically ill patients. Fluorescence intensity increased with time and temperature of storage and was correlated with the decrease in essential fatty acids (lineal correlation between -0.9416 and -0.9996). CONCLUSIONS Enteral formula fat was oxidized during storage, leading to a loss of nutritional value. These formulas should be stored under refrigeration to minimize this loss. Finally, fluorescence measurement proved to be a fast and easy method to assess fat oxidation status.