Determination of Carbohydrate Composition in Lentils Using Near-Infrared Spectroscopy.

Carbohydrates are the main components of lentils, accounting for more than 60% of their composition. Their content is influenced by genetic factors, with different contents depending on the variety. These compounds have not only been linked to interesting health benefits, but they also have a significant influence on the techno-functional properties of lentil-derived products. In this study, the use of near-infrared spectroscopy (NIRS) to predict the concentration of total carbohydrate, fibre, starch, total sugars, fructose, sucrose and raffinose was investigated. For this purpose, six different cultivars of macrosperm (n = 37) and microsperm (n = 43) lentils have been analysed, the samples were recorded whole and ground and the suitability of both recording methods were compared. Different spectral and mathematical pre-treatments were evaluated before developing the calibration models using the Modified Partial Least Squares regression method, with a cross-validation and an external validation. The predictive models developed show excellent coefficients of determination (RSQ > 0.9) for the total sugars and fructose, sucrose, and raffinose. The recording of ground samples allowed for obtaining better models for the calibration of starch content (R > 0.8), total sugars and sucrose (R > 0.93), and raffinose (R > 0.91). The results obtained confirm that there is sufficient information in the NIRS spectral region for the development of predictive models for the quantification of the carbohydrate content in lentils.

Hydrolysis and diffusion of raffinose oligosaccharides family products in chickpeas, lentils, and beans under different pH and temperature steeping conditions.

Soaking pulses in water is a traditional practice widely used both by many households and by the food industry, and depending on the specific conditions used, can effectively reduce α-galactosides. Monitoring changes in α-galactoside content in pulses under different steeping conditions can provide insights into the degradation mechanisms and help overcome the barrier to consumption caused by digestive problems. In this study, we analyzed the impact of steeping at different temperatures (30, 45, 60, 75, and 90 °C) and at different pH (4.0, 5.0, and 6.0) on α-galactosides content in chickpeas, lentils, and beans. Our results showed that the lower the pH, the faster the α-galactosides were reduced. Moreover, steeping at lower temperatures (30 °C and 45 °C) favored hydrolysis of α-galactosides, whereas steeping at higher temperatures (60, 75, and 90 °C) favored diffusion. Soaking at 45 °C at a pH of 4.0 for 3 h resulted in acceptable levels of α-galactosides (less than 1 g/100 g), i.e. a reduction of up to 65 % in chickpeas, 85 % in lentils, and 52 % in beans.

Synthesis, Characterization, X-ray Molecular Structure, Antioxidant, Antifungal, and Allelopathic Activity of a New Isonicotinate-Derived meso-Tetraarylporphyrin.

The present article describes the synthesis of an isonicotinate-derived meso-arylporphyrin, that has been fully characterized by spectroscopic methods (including fluorescence spectroscopy), as well as elemental analysis and HR-MS. The structure of an n-hexane monosolvate has been determined by single-crystal X-ray diffraction analysis. The radical scavenging activity of this new porphyrin against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical has been measured. Its antifungal activity against three yeast strains (C. albicans ATCC 90028, C. glabrata ATCC 64677, and C. tropicalis ATCC 64677) has been tested using the disk diffusion and microdilution methods. Whereas the measured antioxidant activity was low, the porphyrin showed moderate but encouraging antifungal activity. Finally, a study of its effect on the germination of lentil seeds revealed interesting allelopathic properties.

Replacing the animal fat in Bologna sausages using high internal phase emulsion stabilized with lentil protein isolate (Lens culinaris).

High internal phase emulsions (HIPEs) are promising techniques that can replace saturated fat in food without reducing the product's texture, sensory attributes, water-holding capacity, and cooking loss. In the current investigation, 100% pork back fat was replaced by HIPEs formed with lentil protein isolate (LPI) in Bologna sausages. HIPEs were prepared by 25% LPI dispersion (2, 4, 6, and 8%, w/w) and 75% (w/w) soybean oil. HIPEs with higher LPI concentration (4, 6, and 8%, w/w) showed lower droplet size, firmer appearance, and better rheology behavior than 2% LPI. The concentrations LPI (2%, 4%, 6%, and 8%, w/w) led to increased moisture in sausages (FH2, FH4, FH6, and FH8, respectively) compared to the FC. These LPI levels resulted in sausage values for pressed juice similar to the FC and lower energy values than sausages with soybean oil (FO) and pork back fat (FC). Besides, these LPI concentrations (4%, 6%, and 8%, w/w) resulted in a lower oil oxidation level in sausages with HIPEs (FH4, FH6, and FH8, respectively) compared to the control sausage formulation with pork back fat (FC). Bologna sausages elaborated with HIPEs showed emulsion stability values higher than 97%, without significance difference between them. The texture and sensory properties of sausages made with HIPEs were comparable to those made with pork back fat. HIPEs may improve the oxidation stability of the Bologna sausages. These results highlight the effectiveness of HIPEs structured with lentil protein in successfully substituting pork back fat in Bologna sausages with a better nutritional appeal.

Processing parameters, techno-functional properties and potential food application of lentil protein concentrate as an ingredient for the plant-based market.

Lentil (Lens culinaris) is a protein-rich legume consumed worldwide and it also has the potential to become an alternative source of protein ingredient for human nutrition. The aim of this study was to determine the best processing parameters for the whole grain protein wet extraction, as well as to analyze the techno-functional properties, and physical characteristics of the protein concentrate and its flour. It was also evaluated the application of the concentrate into a fish-like croquette. The processing route was carried out by alkaline extraction and acid precipitation of the proteins where the pH, stirring time and solute:solvent ratio were evaluated. The final dried protein concentrate presented 85% protein on dry basis and a mass yield of 14%. The results were reproducible when tested on a first scaling up test. For the techno-functional properties, solubility, water and oil retention capacities, emulsification and foaming capacities and stability, and gelling capacity were tested. As for the food application into fish-like croquettes, the lentil protein showed similar scores for sensory acceptance, flavor and texture when compared to a commercial clean-taste concentrate. The results observed in this study were compatible to other alternative pulse-protein ingredients on the market, positioning lentil protein as a promising alternative protein source to produce ingredients for the plant-based market.

Combination of legume proteins and arabinoxylans are efficient emulsifiers to promote vitamin E bioaccessibility during digestion.

The emulsification potential of plant-based emulsifiers, that is, pea (PPI) and lentil (LPI) proteins (4%), corn arabinoxylans (CAX, 1%), and legume protein-arabinoxylan mixtures (4% proteins + 0.15 or 0.9% CAX), was evaluated by assessing: the surface tension and potential of emulsifiers, emulsifier antinutritional contents, emulsion droplet size, emulsion physical stability, and vitamin E bioaccessibility from 10% oil-in-water emulsions. Tween 80 (2%) was used as a control. All emulsions presented small droplet sizes, both fresh and upon storage, except 4% LPI + 0.9% CAX emulsion that exhibited bigger droplet sizes (d(4,3) of approximately 18.76 µm vs 0.59 µm for the control) because of droplet bridging. Vitamin E bioaccessibility from emulsions stabilized with the combination of 4% PPI and either 0.15% or 0.9% CAX (28 ± 4.48% and 28.42 ± 3.87%, respectively) was not significantly different from that of emulsions stabilized with Tween 80 (43.56 ± 3.71%), whereas vitamin E bioaccessibility from emulsions stabilized with individual emulsifiers was significantly lower.

Submerged fermentation of lentil protein isolate and its impact on protein functionality, nutrition, and volatile profiles.

Fermentation of pulses as a clean processing technique has been reported to have a favorable impact on the functional and nutritional quality of the starting materials. Compared to commonly fermented pulses such as peas and chickpeas, limited information is available on the effect of fermentation on lentils, especially when using a high protein isolate (>80% protein) as compared to seeds or flours. Therefore, in the present work, lentil protein isolate was used as a feedstock for submerged fermentation with Aspergillus niger, Aspergillus oryzae, or Lactobacillus plantarum. After 48 h, the samples showed increased protein content with enhanced solubility and oil-holding capacity. Controlled fermentation, as opposed to spontaneous fermentation, maintained the high foaming capacity; however, all fermented samples had lower foam and emulsion stabilizing properties and reduced water-holding capacity compared to the control. The fermented proteins were also less digestible, possibly due to an increase in phenolics and saponins. New volatile compounds were identified in fermented samples that show promise for improved sensory attributes. Significant differences were observed in specific quality attributes depending on the microbial strain used. Further research is required to better understand the fermentative metabolism of microbial communities when provided high-protein lentil ingredients as growth substrates. PRACTICAL APPLICATION: Fermented lentil protein isolate has promising flavor profiles that may improve its sensory properties for food application.

Investigates the ability of plant extracts from Lens culinaris to protect zucchini from the Zucchini yellow mosaic virus (ZYMV).

Evaluate the impact of extracts from the Lens culinaris plant on a number of physiological and biochemical parameters in squash leaves infected with ZYMV in this work. Compared to the untreated leaves, ZYMV infected leaves showed a range of symptoms, such as severe mosaic, size reduction, stunting, and deformation. Analysis of physiological data revealed that L. culinaris extract lectin therapies and viral infections had an impact on metabolism. Protein, carbohydrate, and pigment levels were all lowered by viral infection. However, phenolic compounds, total protein, total carbohydrates, total amino acids, proline, total chlorophyll and peroxidases levels are considerably elevated with all extract therapies. The other biochemical parameters also displayed a variety of changes. Moreover shoot length, number of leaves and number of flowers was significantly increased compared to viral control in all treatments. The L. culinaris extract treatment increases the plant's ZYMV resistance. This is detectable through reduction of the plants treated with lentil lectin pre and post virus inoculation, reduction in disease severity and viral concentration, and percentage of the infected plants has a virus. All findings demonstrate significant metabolic alterations brought by viral infections or L. culinaris extract treatments, and they also suggest that exogenous extract treatments is essential for activating the body's defences against ZYMV infection.

Single versus multiple metabolite quantification of in vitro starch digestion: A comparison for the case of pulse cotyledon cells.

Different quantification methods for in vitro amylolysis were compared for individual chickpea and lentil cotyledon cells (ICC) as a relevant case study. For the first time, much-applied spectrophotometric methods relying on the quantification of certain functional groups (i.e., DNS, GOPOD) were compared to chromatographic quantification of starch metabolites (HPLC-ELSD). The estimated rate constant and linked initial rates of amylolysis were highly correlated for DNS, GOPOD, and HPLC-ELSD. However, absolute amylolysis levels depended on the applied method and sample-specific metabolite formation patterns. Multiresponse modelling was employed to further investigate HPLC-ELSD metabolite formation patterns. This delivered insight into the relative importance of different amylolysis reactions during in vitro digestion of pulse ICC, proving that maltotriose and maltose formation determined the overall amylolysis rate in this case. Multiresponse reaction rate constants of maltotriose and maltose formation were highly correlated to single response amylolysis rate constants (and initial rates) obtained for all three quantification methods.

Lentil protein isolate (Lens culinaris) subjected to ultrasound treatment combined or not with heat-treatment: structural characterization and ability to stabilize high internal phase emulsions.

This study evaluated the effect of ultrasound treatment combined or not with heat treatment applied to lentil protein isolate (LPI) aiming to enhance its ability to stabilize high internal phase emulsions (HIPE). LPI dispersion (2%, w/w) was ultrasound-treated at 60% (UA) and 70% (UB) amplitude for 7 min; these samples were subjected to and then heat treatments at 70 °C (UAT70 and UBT70, respectively) or 80 °C (UAT80 and UBT80, respectively) for 20 min. HIPEs were produced with 25% untreated and treated LPI dispersions and 75% soybean oil using a rotor-stator (15,500 rpm/1 min). The LPI dispersions were evaluated for particle size, solubility, differential scanning calorimetry, electrophoresis, secondary structure estimation (circular dichroism and FT-IR), intrinsic fluorescence, surface hydrophobicity, and free sulfhydryl groups content. The HIPEs were evaluated for droplet size, morphology, rheology, centrifugal stability, and the Turbiscan test. Ultrasound treatment decreased LPI dispersions' particle size (∼80%) and increased solubility (∼90%). Intrinsic fluorescence and surface hydrophobicity confirmed LPI modification due to the exposure to hydrophobic patches. The combination of ultrasound and heat treatments resulted in a reduction in the free sulfhydryl group content of LPI. HIPEs produced with ultrasound-heat-treated LPI had a lower droplet size distribution mode, greater oil retention values in the HIPE structure (> 98%), lower Turbiscan stability index (< 2), and a firmer and more homogeneous appearance compared to HIPE produced with untreated LPI, indicating higher stability for the HIPEs stabilized by treated LPI. Therefore, combining ultrasound and heat treatments could be an effective method for the functional modification of lentil proteins, allowing their application as HIPE emulsifiers.

Study of the changes on the physicochemical properties of isolated lentil starch during germination.

In this work, the changes in the composition of the flours and in the morphological, structural, thermal, vibrational, rheological, and functional properties of the isolated lentil starch during the germination process were investigated. The fiber, fat, and ash content of the flours decreased and the protein content increased, while the apparent amylose content of the starch granules remained constant. Using scanning electron microscopy (SEM), the starch granules remained intact during germination, and no enzymatic activity of α- and ß-amylases was observed. X-ray diffraction shows that the starch has nanocrystals with hexagonal structure which predominate over the nanocrystals with orthorhombic structure and are classified as C-type starch. The most important result is that these nanocrystals do not play an important role during germination. As the germination time progresses, differential scanning calorimetry (DSC) shows a decrease in the gelatinization temperature (Tp) of the starch, ranging from 70.34 ± 0.25 °C for the native lentil starch to values of 67.16 ± 0.37 °C for the starch on the fourth day of germination (ILS4), this transition being related to the solvation of the nanocrystals. On the other hand, the pasting profiles show no significant changes during germination, indicating that no significant changes in starch content occur during germination. Starch degradation is essential for the production of malt for fermented beverages. This fact makes sprouted lentils not a candidate for the short-term fermentation required in the beverage industry.

Characterization of starches isolated from Mexican pulse crops: Structural, physicochemical, and rheological properties.

This work aimed to characterize and compare the physicochemical properties of four pulse starches: bean, chickpea, lentil, and pea. Chemical proximate analysis, elemental composition, morphological grain characterization, crystalline structure, thermal analysis, FTIR analysis, and pasting properties were conducted. The proximate analysis shows that these starches have low fat, mineral, and protein content but high amylose values ranging from 29 to 36 % determined by colorimetry. Despite the high amylose content, the starches did not exhibit the typical behavior of an amylose-rich starch, with high peak viscosity and low breakdown and setback. It was found that this behavior was likely due to the large granule size of the ellipsoidal, spherical, and kidney-shaped granules and the high content of some minerals such as Na, Mg, K, Fe, Mn, P, and Si. The study also found that all pulse starches simultaneously contain monoclinic and hexagonal crystals, making them C-type starches. The findings were verified through the Rietveld analyses of X-ray diffraction patterns and differential scanning calorimetry, in which bimodal endothermic peaks evidenced both types of crystals being gelatinized.

Co-ingestion of Cereals and Legumes during Infant Complementary Feeding: Starch and Protein in vitro Digestion.

This study explores the impact of co-ingesting cereals and legumes on starch and protein during simulated infant in vitro digestion. Various legumes (chickpeas, lentils, peas) were added to cereals (durum wheat, brown rice, white maize), and their effects on starch and protein hydrolysis were analyzed. Substituting 50% of cereal with legumes increased proteins, minerals, and dietary fiber. Infant food with legumes exhibited smoother pasting properties. Legumes in cereal purées led to varying starch hydrolysis trends, with the lowest values in durum wheat with chickpea and all cereal blends with peas. Resistant starch levels exceeding 50% were found in infant food samples. Digested protein hydrolysis increased with legumes in durum wheat, except for peas. Brown rice mixtures decreased significantly compared to the control with chickpeas (61%) and peas (42%), while lentil blends increased by 46%. Legumes generally did not significantly affect starch bioavailability, even with α-amylase inhibitors. Lentil-cereal purées could enhance infant food nutritional value.

The effect of germinated black lentils on cookie quality by applying ultraviolet radiation and ultrasound technology.

Black lentils contain protein, carbohydrates, dietary fiber, minerals, and vitamins, as well as phytochemicals and various bioactive compounds. Ultraviolet (UV) radiation and ultrasound (US) methods are innovative technologies that can be used to increase the efficiency of the germination process in grains and legumes. To improve the nutritional value and bioactive compounds of the cookies, black lentils germinated by applying UV radiation and US technology were used in the cookie formulation. Before the germination process, UV, US, and their combination (UV+US) were applied, and pretreated and unpretreated germinated black lentil flours were used at a level of 20% in the cookie formulation. The results revealed that pretreatment application increased the total phenolic content and antioxidant activity more than the lentil sample germinated without any treatment. In addition, the pretreatments applied further reduced the amount of phytic acid in black lentils and the lowest phytic acid content was obtained with the UV-US combination. Compared to cookies containing unpretreated germinated black lentil flour, higher L* values and lower a* values were obtained in the cookie samples containing pretreated germinated black lentil flour. Cookies containing all pretreated germinated lentils generally exhibited higher Ca and K content. This study demonstrated that UV radiation and US improved the nutritional value and bioactive components of the germinated black lentil flour and the cookies in which it was used, compared to the black lentils germinated without any treatment. PRACTICAL APPLICATION: Pretreatment of black lentils with UV/US application before germination resulted in a greater increase in total phenolic content and antioxidant activity compared to the control sample. The applied pretreatments caused a further decrease in the amount of phytic acid in black lentil samples. Black lentils germinated with the UV+US combination revealed higher Ca, Fe, K, and Mg content compared to the sample germinated without any treatment.

Effect of different physical pre-treatments on physicochemical and techno-functional properties, and on the antinutritional factors of lentils (Lens culinaris spp).

Lentils have a valuable physicochemical profile, which can be affected by the presence of antinutrients that may impair the benefits arising from their consumption. Different treatments can be used to reduce these undesirable compounds, although they can also affect the general composition and behaviour of the lentils. Thus, the effect of different processing methods on the physicochemical and techno-functional properties, as well as on the antinutritional factors of different lentil varieties was studied. Phytic acid was eliminated during germination, while tannins and trypsin inhibitors are mostly affected by cooking. Functional properties were also altered by processing, these being dependent on the concentration of different nutrients in lentils. All the studied treatments affected the physicochemical profile of lentils and their functional properties. Cooking and germination appear to be the most effective in reducing antinutritional factors and improving the physicochemical profile of the lentils, meeting the current nutritional demands of today's society.

Fibrillization of lentil proteins is impacted by the protein extraction conditions and co-extracted phenolics.

Legume proteins can be induced to form amyloid-like fibrils upon heating at low pH, with the exact conditions greatly impacting the fibril characteristics. The protein extraction method may also impact the resulting fibrils, although this effect has not been carefully examined. Here, the fibrillization of lentil protein prepared using various extraction methods and the corresponding fibril morphology were characterized. It was found that an acidic, rather than alkaline, protein extraction method was better suited for producing homogeneous, long, and straight fibrils from lentil proteins. During alkaline extraction, co-extracted phenolic compounds bound proteins through covalent and non-covalent interactions, contributing to the formation of heterogeneous, curly, and tangled fibrils. Recombination of isolated phenolics and proteins (from acidic extracts) at alkaline pH resulted in a distinct morphology, implicating a role for polyphenol oxidase also in modifying proteins during alkaline extraction. These results help disentangle the complex factors affecting legume protein fibrillization.

Trehalose-conjugated lentil-casein protein complexes prepared by structural interaction: Effects on water solubility and protein digestibility.

The two limiting factors for lentil protein utilization are water solubility and digestibility. In this study, we utilized two non-thermal techniques: (1) protein complexation of lentil and casein proteins using the pH-shifting method and (2) protein conjugation with trehalose to produce trehalose-conjugated lentil-casein protein complexes (T-CPs) with enhanced water solubility and digestibility. The protein structure of the T-CPs was analyzed for secondary protein structure, conformation protein, and tertiary protein structure using Fourier-transform infrared, UV, and fluorescence spectroscopies, respectively. The surface hydrophobicity and surface charge of T-CPs solution at pH 7.0 changed significantly (P < 0.05). Using these two non-thermal techniques, the water solubility and digestibility of T-CPs increased significantly (P < 0.05) by 85 to 89 % and 80 to 85 %, respectively. The results of this study suggested that these non-thermal techniques could enhance the surface and protein structure properties, improving water solubility and digestibility.

Gluten-free lentil cakes with optimal technological and nutritional characteristics.

BACKGROUND: The celiac population usually struggle finding nutritive gluten-free (GF) baked goods. GF foods can be improved using legume flours. Eleven GF cake formulations were elaborated according to different percentages of lentil flour (LF), corn flour (CF) and rice flour (RF) using a simplex lattice design. Water holding capacity and particle size of flours were evaluated. Moisture, aw, pH, specific volume, texture profile, relaxation, color and alveolar characteristics were determined for crumbs of all formulations. An optimization process was used to enhance the technological and nutritional attributes, selecting the three best formulations containing LF: 46% LF + 54% RF (CLF+RF); 49% LF + 51% CF (CLF+CF); and 100% LF (CLF), evaluated in their proximal composition and sensory characteristics. Linear and quadratic models for predicting the behavior of GF lentil cakes were obtained. RESULTS: LF and CF could favor water incorporation and show more resistance to enzymatic digestion than RF. Formulations with LF showed an improvement in specific volume and alveolar parameters, while use of RF led to better cohesiveness, elasticity and resilience but with a deterioration in chewiness and firmness. CLF can be labeled as high in protein and fiber and presented the lowest amounts of lipids, carbohydrates and energy content. Consumer preference leaned towards CLF+RF. CONCLUSION: It was possible to elaborate GF cakes using LF, obtaining nutritive products that can be offered to people intolerant to gluten ingestion. © 2024 Society of Chemical Industry.

Nutritional, chemical, and antioxidant screening of selected varieties of lentils (Lens culinaris spp.) from organic and conventional agriculture.

BACKGROUND: Lentils are an ancient legume established worldwide for direct consumption and with great potential for application in food processing. In addition, it is a sustainable crop owing to its ability to scavenge nitrogen and carbon, and it improves the nutrient status of the soil. A diet rich in lentils has been linked to significant health benefits. However, the composition of lentils can be influenced by both the lentil variety and the growing conditions. The aim of this work was to evaluate the nutritional profiles and antioxidant potential, as well as the impact that the type of cultivation (conventional or organic) and the variety could have on these parameters, in different lentil varieties. RESULTS: Overall, carbohydrates are the major macronutrients in all varieties, with notable amounts of fibre (11.62-27.36%) and starch (41.98-50.27%). High amounts of protein and ash were also identified, particularly in the Beluga variety, with 21.9-23.3 and 1.38-1.82 g 100 g-1 fresh weight, respectively. Fructose and sucrose were detected (high-performance liquid chromatography (HPLC) with refraction index detection), along with oxalic, quinic, malic, and shikimic acids (ultra-fast liquid chromatography with photodiode array detection), and α- and γ-tocopherol isoforms (HPLC with fluorescence detection). Fatty acid methyl ester assessment showed the prevalence of polyunsaturated fatty acids (33.5-46.3%). Good antioxidant capacity (thiobarbituric acid reactive substances and oxidative haemolysis inhibition assay) was also noted. CONCLUSION: The results obtained showed that all the varieties analysed are an excellent source of fibre and have a good antioxidant capacity. Lentil variety has a greater influence on its nutritional composition than the type of cultivation. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Folate content and retention in selected raw and processed foods / Contenido de folatos y retención en determinados alimentos crudos y procesados

Adequate intake of folate reduced the risk of abnormalities in early embryonic brain development such as the risk of malformations of the embryonic brain/spinal cord, collectively referred to as neural tube defects (NTDs). Folate is extremely sensitive to destruction by heat, oxidation and UV light. The purpose of this study was to evaluate the use of different extraction procedures and enzymatic treatment to determine folate concentrations in variety of foods using a microbiological assay (MA) with Lactobacillus rhamnosus as the test organism. This study also aimed to evaluate the retention of folate in foods after using different cooking processes. Nine of the most commonly consumed foods in Argentina and that contain folate were analyzed: broccoli, spinach, potato, lentil, soy (raw and boiled); hen whole egg and yolks (raw, boiled and fried); beef liver (raw and cooked); strawberry (raw) and white bread. For this study, rat plasma (RP) and human plasma (HP) conjugases together with acetate and phosphate buffers were tested. In extraction step for all analyses, RP conjugase was selected since it was easily available in our laboratory and small quantities were required. The acetate buffer was chosen since better growth and more reproducible results were obtained in the different conditions assayed. The results allowed the foods to be grouped into a) rich sources of folate: hen eggs, yolks, spinach, soybean (raw) and strawberry (100 and 350mg/100g fresh weight (FW); b) good sources of folate: broccoli (raw), soybean (boiled), lentils (raw) and potato (56 to 83mg/100g FW) and c) moderate sources of folate: broccoli, lentils (boiled), white breads, onions and beef liver (15 to 30mg/100g FW). The folate retention was in the range 14-99% according to both type of food and method of processing. Contents and losses of folate vary widely according to type of food and cooking method.

La ingesta adecuada de folatos reduce el riesgo de las anormalidades en el desarrollo temprano del cerebro embrionario, tales como el riego de malformaciones en el cerebro/médula espinal, conocidas en conjunto como defectos del tubo neural (NTDs). Los folatos son extremadamente sensibles al tratamiento con calor, la oxidación y la luz UV. El objetivo de este trabajo fue evaluar el uso de diferentes procedimientos de extracción y de tratamientos enzimáticos para determinar el contenido de folato en distintos alimentos empleando un método microbiológico que utiliza el microorganismo Lactobacillus rhamnosus. En este trabajo se evaluó también la retención de folatos en alimentos sometidos a diferentes procesos de cocción. Se analizaron 9 de los alimentos que contienen folatos y más comúnmente consumidos en Argentina: brócoli, espinaca, papa, lente ja, soja (crudos y cocidos): huevo entero de gallina y yema (crudo, hervido y frito). Bife de hígado vacuno (crudo y cocido); frutillas (crudas) y pan: blanco. Se probó para este estudio conjugasas de plasma de rata (PR) y de plasma humano (PH) conjuntamente con buffers fosfato y acetato. En la extracción para todos los análisis se escogió la conjugasa de PR por ser accesible para nuestro laboratorio y por que se utiliza en pequeñas cantidades. El buffer acetato fue elegido debido a que se obtuvo resultados más reproducibles y un mejor crecimiento en las diferentes condiciones ensayadas. Los resultados permitieron agrupar los alimentos en: a) fuente rica de folatos: huevo y su yema, espinaca, soja (cruda) y frutilla (100 a 350mg/100g peso fresco); b) fuente buena de folatos: brócoli (crudo), soja (hervidas), lentejas (cruda) y papa (cruda y hervida) (56 a 83mg/100g peso fresco) y c) fuente moderada de folatos: brócoli y lentejas (hervidos), bife de hígado, pan blanco y cebollas (15 a 30mg/100g peso fresco). La retención de folato estuvo en el rango de 14-99% de acuerdo al tipo de alimento y el método de procesado. El contenido de folato y sus perdidas fueron muy variables dependiendo del alimento y del método de cocción empleados.