Carotenoid content and deposition efficiency in yolks of laying hens fed with dent corn hybrids differing in grain hardness and processing.

Yolk carotenoid profile reflects the hen diet when corn grain is the only source of carotenoids, but corn origin and processing may affect carotenoid utilization. In the present study, 2 commercial dent corn hybrids differing in grain hardness (soft- and hard-type) were dried at low (40°C) and high (85°C) temperature and ground through a 5- and 9-mm sieve to investigate their effects on carotenoid bioavailability in laying hens. With 3 hens per cage, 168 Lohmann Brown laying hens were allocated to 8 dietary treatments (2 hybrids × 2 drying temperatures × 2 grinding sieves) in a completely randomized design (8 treatments × 7 cages). The trial lasted 8 wk, during which eggs were collected for analysis every 3 d until carotenoid content stabilized, and then once a week until the end of the experiment. The carotenoid profile of the experimental diets and yolks was analyzed using an HPLC method and deposition efficiency was calculated based on carotenoid contents, yolk weight, egg production and diet intake. The deposition efficiency for lutein, zeaxanthin, α- and ß-cryptoxanthin, and ß-carotene averaged 27.37, 18.67, 6.29, 3,32, and 0.94%, respectively. As expected, the tested hybrids highly affected the carotenoid content in egg yolk due to their differences in carotenoid profile. Interestingly, hard- and soft-type hybrids differed in the deposition efficiency for all individual carotenoids but not for the total carotenoids. High grain drying temperature tended to increase the bioavailability of lutein and zeaxanthin in both hybrids. For the hard-type hybrid, the content of ß-carotene in egg yolk was higher when grains were dried at a high temperature, while the opposite response was found in the soft-type hybrid. The effect of grinding sieve size was important for the zeaxanthin bioavailability in the soft-type hybrid only. In conclusion, our findings showed that corn hybrid had a primary influence on the carotenoid content in the yolks of laying hens, but grain processing may change the bioavailability of carotenoids.

Effects of Animal Diet and Processing Methods on the Quality Traits of Dry-Cured Ham Produced from Turopolje Pigs.

The Turopolje pig (TP) is a local Croatian pig breed that almost became extinct in the second half of the 20th century. Today, the TP is still endangered, and a new conservation strategy based on products with higher added value is needed to preserve the breed. There is little information on the quality of TP meat products such as smoked and dry-cured ham, including the impact of natural feeds or processing innovations such as smoke reduction. This study, therefore, investigated the effects of the animal's diet (either conventionally fed or acorn-supplemented) and the processing method (standard or lightly smoked) on the quality traits of dry-cured TP ham. Twenty hams, evenly distributed among the treatments, were processed for 15 months and then analysed for physicochemical and textural traits, volatiles and sensory profile. The hams from acorn-supplemented pigs lost less weight during processing (p ≤ 0.05). Otherwise, the diet had no significant effect on most examined ham traits. The exceptions were protein content and the texture parameter hardness, which decreased (p ≤ 0.05), and the degree of proteolysis and colour parameters, which increased (p ≤ 0.05) as a result of acorn supplementation. However, these effects were generally small and varied between the inner (m. biceps femoris) and outer (m. semimembranosus) muscles. Furthermore, acorn supplementation was associated with less typical ham odour and lower sensory scores for sweetness and colour uniformity (p ≤ 0.05). The smoke reduction had no effect on the physicochemical and colour properties but resulted in a significant reduction (p ≤ 0.05) in the volatile phenolic compounds and an improved texture to the hams. This was reflected both in reduced (p ≤ 0.05) hardness, identified in the instrumental analysis, and in an increased (p ≤ 0.05) softness, solubility and moistness, identified in the sensory evaluation. To summarize, the quality of the TP ham under the conditions studied was only slightly affected by acorn supplementation, whereas reduced smoking had a more significant effect, which was mainly reflected in an improved texture.

Carotenoid degradation rate in milled grain of dent maize hybrids and its relationship with the grain physicochemical properties.

Carotenoids in maize grain degrade during storage, but the relationship between their stability and the physicochemical properties of the grain is unclear. Therefore, the carotenoid degradation rate in milled grain of three dent hybrids differing in grain hardness was evaluated at various temperatures (-20, 4 and 22 °C). The carotenoid degradation rate was calculated using first-order kinetics based on the content in the samples after 7, 14, 21, 28, 42, 56, 70 and 90 days of storage and related to the physicochemical properties of the grain. The highest grain hardness was found in the hybrid with the highest zein and endosperm lipid concentration, while the lowest grain hardness was found in the hybrid with the highest amylose content and the specific surface area of starch granule (SSA). As expected, carotenoids in milled maize grain were most stable at -20 °C, followed by storage at 4 and 22 °C. Tested hybrids differed in the degradation rate of zeaxanthin, α-cryptoxanthin and ß-carotene, and these responses were also temperature-dependent. In contrast, all hybrids showed similar degradation rate for lutein and ß-cryptoxanthin regardless of the storage temperature. Averaged over the hybrids, the degradation rate for individual carotenoids ranked as follows: lutein < zeaxanthin < α-cryptoxanthin < ß-cryptoxanthin < ß-carotene. The lower degradation rate for most carotenoids was mainly associated with a higher content of zein and specific endosperm lipids, with the exception of zeaxanthin, which showed an opposite pattern of response. Degradation rate for lutein and zeaxanthin negatively correlated with SSA, but interestingly, small starch granules were positively associated with higher degradation rate for mostcarotenoids. Dent-type hybrids may differ significantly in carotenoid degradation rate, which was associated with specific physicochemical properties of the maize grain.

Genetic Variability in Carotenoid Contents in a Panel of Genebank Accessions of Temperate Maize from Southeast Europe.

Carotenoids are an abundant group of lipid-soluble antioxidants in maize kernels. Maize is a key target crop for carotenoid biofortification focused on using conventional plant breeding in native germplasm of temperate areas traced back partially to traditional cultivars (landraces). In this study, the objectives were to determine the variability of lutein (LUT), zeaxanthin (ZEA), α-cryptoxanthin (αCX), ß-cryptoxanthin (ßCX), α-carotene (αC), and ß-carotene (ßC) contents in the grain of 88 accessions of temperate maize from the Croatian genebank, and to evaluate the relationships among the contents of different carotenoids as well as the relationships between kernel color and hardness and carotenoid content. Highly significant variability among the 88 accessions was detected for all carotenoids. On average, the most abundant carotenoid was LUT with 13.2 µg g-1 followed by ZEA with 6.8 µg g-1 dry matter. A Principal Component Analysis revealed a clear distinction between α- (LUT, αCX, and αC) and ß-branch (ZEA; ßCX, and ßC) carotenoids. ß-branch carotenoids were positively correlated with kernel color, and weakly positively associated with kernel hardness. Our results suggest that some genebank accessions with a certain percentage of native germplasm may be a good source of carotenoid biofortification in Southeast Europe. However, due to the lack of association between LUT and ZEA, the breeding process could be cumbersome.

Feeding Black Pepper (Piper nigrum) or Exogenous Xylanase Improves the Blood Lipid Profile of Broiler Chickens Fed Wheat-Based Diets.

This study aimed to determine the impact of dietary black peppercorn (BP) and xylanase (XYL) alone or in combination on growth performance, dietary energy, nutrient digestibility and blood lipid profile when fed to male Ross 308 broiler chickens from the ages of 7 to 21 d. A wheat-soy-based basal feed that was formulated to be 0.42 MJ lower in metabolizable energy (ME) was mixed. The basal feed was then split into four batches, with the first batch set aside as the basal control; the second batch was supplemented with freshly milled BP; the third batch was supplemented with XYL; the fourth batch was supplemented with both BP and XYL, as in the previous two batches. Each diet was fed to eight pens, with two birds in a pen, following randomization. Feeding BP reduced bird growth and most of the digestibility coefficients but increased blood high-density lipoprotein (p < 0.05). Dietary XYL increased bird growth, dietary ME and nutrient digestibility (p < 0.05). In addition, XYL increased hepatic carotenoids and coenzyme Q10, but reduced blood low-density lipoprotein (p < 0.05). There were no BP by XYL interactions (p > 0.05) observed. Further research is needed to identify the optimum level of BP in broiler diets.

Bioaccessibility of Tocols in Commercial Maize Hybrids Determined by an In Vitro Digestion Model for Poultry.

Despite the high proportion of maize grain in animal diets, the contribution made by maize phytochemicals is neglected. Tocols and their contribution to the vitamin E content of animal diets are one example, exacerbated by sparse information on the tocol bioaccessibility of commercial hybrids. In this study, the contents of individual and total tocols and their bioaccessibility were determined in the grain samples of 103 commercial hybrids using a standardized INFOGEST digestion procedure. In the studied hybrids, total tocol content ranged from 19.24 to 54.44 µg/g of dry matter. The contents of micellar α-, γ-, δ-tocopherols, γ-tocotrienol, and total tocols correlated positively with the corresponding contents in the grain samples of the studied hybrids. In contrast, a negative correlation was observed between the bioaccessibility of γ- tocopherol, α- and γ-tocotrienol, and total tocols, along with the corresponding contents in the grain of studied hybrids. The highest bioaccessibility was exhibited by γ-tocotrienol (532.77 g/kg), followed by δ-tocopherol (529.88 g/kg), γ-tocopherol (461.76 g/kg), α-tocopherol (406.49 g/kg), and α-tocotrienol (359.07 g/kg). Overall, there are significant differences in the content and bioaccessibility of total and individual tocols among commercial maize hybrids, allowing the selection of hybrids for animal production based not only on crude chemical composition but also on the content of phytochemicals.

Stevia (Stevia rebaudiana) Improves Carotenoid Content in Eggs When Fed to Laying Hens.

Stevia rebaudiana Bertoni is a shrub with leaves that have a high concentration of carotenoids such as lutein and zeaxanthin. Egg yolks are a bioavailable source of lutein and zeaxanthin. The consumption of these carotenoids has been linked with improved human health. To investigate the impact of dried stevia leaves at 0%, 1% and 2% on the quality variables, the chemical composition and antioxidant content of eggs, the experiment involved 90 Hy-Line Brown laying hens, housed in 30 enriched layer cages, in groups of three from 22 to 26 weeks of age. The impact on the internal qualities of stored eggs was also examined. Yolks from hens fed stevia had an enriched color compared with the controls. At the end of the experiment, the whole egg, without shell, of birds fed 2% stevia had a higher total carotenoid content (p < 0.001) compared with birds fed 1% and 0% stevia, i.e., 5.16 (µg/g), 4.23 (µg/g) and 2.96 (µg/g), respectively. Storage reduced albumen height and increased albumen pH (p < 0.001). Stevia supplementation did not interact (p > 0.05) with storage time among the egg quality variables. Consuming eggs from hens fed stevia may increase carotenoids in human diet.

Selected Phenolic Acids Inhibit the Initial Growth of Ambrosia artemisiifolia L.

This study aimed to investigate whether different doses of specific phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, and p-coumaric acid), alone or in combination, can inhibit the early growth of the common ragweed (Ambrosia artemisiifolia L., Asterales: Asteraceae). A seed bioassay was performed in Petri dishes and placed in a climate chamber to assess the effects of five dose levels of phenolic acids to radicle and shoot length, as well seedling biomass of A. artemisiifolia. The lowest dose of phenolic acid corresponded to the natural phenolic acid concentration previously reported in dry plant tissue samples from Brassicaceae cover crop plants. Results show that the inhibition of the early growth of A. artemisiifolia depends strongly on phenolic acid. Across different treatments, high doses of phenolic acids significantly shortened shoots and radicles, as well as reduced seedling biomass. Treating seeds with ferulic acid alone, vanillic acid alone, p-hydroxybenzoic acid alone, or a mixture of all phenolic acids significantly reduced all early growth parameters. The estimated effective dose for the 50% inhibition (ED50) of radicle growth in A. artemisiifolia seedlings was 368.39 ± 59.85 × 10-8 mol with ferulic acid, 135.41 ± 17.65 × 10-8 mol with p-coumaric acid, 810.36 ± 134.15 × 10-8 mol with p-hydroxybenzoic acid, and 160.11 ± 12.30 × 10-8 mol with the combination of all phenolic acids.

A comprehensive review on carotenoids in foods and feeds: status quo, applications, patents, and research needs.

Carotenoids are isoprenoids widely distributed in foods that have been always part of the diet of humans. Unlike the other so-called food bioactives, some carotenoids can be converted into retinoids exhibiting vitamin A activity, which is essential for humans. Furthermore, they are much more versatile as they are relevant in foods not only as sources of vitamin A, but also as natural pigments, antioxidants, and health-promoting compounds. Lately, they are also attracting interest in the context of nutricosmetics, as they have been shown to provide cosmetic benefits when ingested in appropriate amounts. In this work, resulting from the collaborative work of participants of the COST Action European network to advance carotenoid research and applications in agro-food and health (EUROCAROTEN, www.eurocaroten.eu, https://www.cost.eu/actions/CA15136/#tabs|Name:overview) research on carotenoids in foods and feeds is thoroughly reviewed covering aspects such as analysis, carotenoid food sources, carotenoid databases, effect of processing and storage conditions, new trends in carotenoid extraction, daily intakes, use as human, and feed additives are addressed. Furthermore, classical and recent patents regarding the obtaining and formulation of carotenoids for several purposes are pinpointed and briefly discussed. Lastly, emerging research lines as well as research needs are highlighted.

European Database of Carotenoid Levels in Foods. Factors Affecting Carotenoid Content.

Many studies indicate that diets including carotenoid-rich foods have positive effects on human health. Some of these compounds are precursors of the essential nutrient vitamin A. The present work is aimed at implementing a database of carotenoid contents of foods available in the European market. Factors affecting carotenoid content were also discussed. Analytical data available in peer-reviewed scientific literature from 1990 to 2018 and obtained by HPLC/UHPLC were considered. The database includes foods classified according to the FoodEx2 system and will benefit compilers, nutritionists and other professionals in areas related to food and human health. The results show the importance of food characterization to ensure its intercomparability, as large variations in carotenoid levels are observed between species and among varieties/cultivars/landraces. This highlights the significance of integrating nutritional criteria into agricultural choices and of promoting biodiversity. The uncertainty quantification associated with the measurements of the carotenoid content was very rarely evaluated in the literature consulted. According to the EuroFIR data quality evaluation system for food composition tables, the total data quality index mean was 24 in 35, reflecting efforts by researchers in the analytical methods, and less resources in the sampling plan documentation.

Plant Carotenoids as Pigment Sources in Laying Hen Diets: Effect on Yolk Color, Carotenoid Content, Oxidative Stability and Sensory Properties of Eggs.

The aim of this study was to evaluate the effect of a supplementation diet for hens consisting of dried basil herb and flowers of calendula and dandelion for color, carotenoid content, iron-induced oxidative stability, and sensory properties of egg yolk compared with commercial pigment (control) and marigold flower. The plant parts were supplemented in diets at two levels: 1% and 3%. In response to dietary content, yolks from all diets differed in carotenoid profile (p < 0.001). The 3% supplementation level resulted in a similar total carotenoid content as the control (21.25 vs. 21.79 µg/g), but by 3-fold lower compared to the 3% marigold (66.95 µg/g). The tested plants did not achieve yolk color fan values as the control (13.47) or 3% marigold (11.47), and among them, calendula had the highest values (9.73). Despite the low carotenoid content in diets supplemented with basil herb, iron-induced malondialdehyde (MDA) concentration was low as for marigold (on average 106.83 vs. 92.68 ng/g after 250 min). The treatments differed in sensory color scores for fresh and hard-boiled yolks and flavor while other sensory properties were similar. In conclusion, the supplementation of plants in a hen diet may result in yolks containing carotenoids and other compounds showing a high antioxidant effect.

Feeding dry stevia leaf (Stevia rebaudiana) or xylanase improves the hepatic antioxidative status of broiler chickens.

Four diets, formulated with and without stevia and with and without exogenous xylanase, following a 2 × 2 factorial design, were prepared. Each diet was fed ad libitum to birds in eight pens (three birds in each pen) in a randomised block design. It was found that birds fed xylanase grew faster, used the feed more efficiently and had an increased concentration of hepatic α-tocopherol and vitamin E concentrations (P < 0.05). Feeding stevia did not affect growth performance (P > 0.05), but increased hepatic CoQ10 (P = 0.05), lutein, zeaxanthin and total carotenoids (P < 0.001) concentrations. There were no dietary stevia by xylanase interactions (P > 0.05) for any of the studied variables. The results showed that alone, dietary stevia and dietary xylanase can improve the antioxidative status of birds through enhancing dietary antioxidant availability.

Feeding dihydroquercetin and vitamin E to broiler chickens reared at standard and high ambient temperatures.

The use of natural antioxidants, in particular polyphenols such as dihydroquercetin (DHQ), in animal nutrition has recently increased in popularity. This may partly be due to the risk of increased incidences of heat stress associated with raising livestock in warmer ambient temperatures, facilitated by global warming, reducing antioxidant capacity. The current research demonstrates the effect of dietary DHQ, vitaminEand standard or high ambient temperatures on growth performance, energy and nutrient metabolism, gastrointestinal tract (GIT) development, jejunal villus morphometry and antioxidant status in broiler chickens. Each of the four experimental diets was fed to 16 pens of five birds, which were allocated to four rooms (four pens in each room). The temperature in two rooms was maintained at aconstant 35°C (high temperature; HT), and the temperature in the other two rooms was gradually reduced from 27°C at 7 dof age to 22°C at 20 dof age (standard temperature; ST). Rearing birds at HT reduced feed intake, weight gain, weight of small intestine, total GIT, liver, spleen, heart, villus height, villus surface area and lowered blood glutationperoxidase (GSH-Px). Dietary DHQ increased blood GSH-Px and total antioxidant status, increased heart weight and reduced caecal size. When fed separately, DHQ and vitamin E improved hepatic vitamin E concentration. Feeding vitamin Eincreased spleen and liver weights. When fed together, DHQ and vitamin Ereduced villus height, villus height to crypt depth ratio and villus surface area. Temperature and antioxidants did not affect energy and nutrient metabolism. There were no effects of dietary antioxidants on growth performance of broiler chickens and there were no mortalities. At present, it is unclear if feeding antioxidants (in particular DHQ) at different levels, using different dietary formulations, and rearing birds under arange of environmental conditions may be effective at enhancing production performance and bird health in hot ambient climates.

Sensitivity of yellow foxtail (Setaria glauca L.) and barnyardgrass (Echinochloa crus-galli L.) to aqueous extracts or dry biomass of cover crops.

BACKGROUND: The common weeds Echinochloa crus-galli L. and Setaria glauca L. were studied for their sensitivity to aqueous extracts or dry biomass of the following cover crops (CCs): Brassicaceae (Sinapis alba, Raphanus sativus var. Oleiformis, Camellina sativa), Fagopyrum esculentum and Guizotia abyssinica. RESULTS: Treating E. crus-galli with aqueous extracts of mixed CCs or individual brassica CC significantly reduced germination. Treating S. glauca with aqueous extracts of C. sativa or G. abyssinicia reduced germination. Aqueous extracts of all CCs significantly reduced radicle length of E. crus-galli and S. glauca, with C. sativa and mixed CCs showing the greatest effect. Aqueous extracts of nearly all CCs delayed start and middle germination of E. crus-galli and S. glauca, with S. alba and R. sativus showing the strongest effects. Aqueous extracts of Brassicaceae leaf and flower significantly reduced germination, coleoptile length, radicle length and seedling biomass of E. crus-galli and S. glauca. Brassicaceae leaves and flowers contained higher phenolics than other tissues. Adding 4 or 8% S. alba and R. sativus dry powder to soil significantly reduced growth of E. crus-galli and S. glauca; even concentrations of 1% measurably slowed growth of E. crus-galli. CONCLUSIONS: Brassicaceae may be allelopathic to S. glauca and E. crus-galli. Aqueous extracts of leaves and flowers showed greater phytotoxic activity than other tissues and also contained more phenolics. Therefore Brassicaceae CCs may be most effective against S. glauca and E. crus-galli if incorporated into soil during their flowering stage. © 2020 Society of Chemical Industry.

Effect of starch properties and zein content of commercial maize hybrids on kinetics of starch digestibility in an in vitro poultry model.

BACKGROUND: The kinetics of starch digestion is a key determinant of poultry performance. Research so far has shown that starch digestibility kinetics depends on the molecular structure of starch but also on the properties of the complex matrix in which starch granules are embedded in most feedstuffs. However, the manner in which genotype differences in the same plant affect starch digestibility kinetics has not yet been addressed. The present study explored the extent to which the starch digestibility rate in commercial high-yielding maize hybrids depended on amylose / amylopectin content, starch granule size and shape, and zein in total starch (TS) content. RESULTS: Hybrids differed in all the traits examined, giving the following ranges: amylose content, 165-207 g kg-1 DM; zein in TS content, 70-89 g kg-1 DM; starch granule equivalent diameter, 11.5-12.3 µm, and in vitro starch digestion rate, 1.22-1.44 h-1 . The starch digestion rate correlated negatively with zein in TS content (r = -0.36) and positively with equivalent diameter (r = 0.45). The negative correlation between starch digestion rate and zein in TS suggests that some zein remained after grinding and pepsin incubation and acted as a barrier to amylolytic enzymes. CONCLUSIONS: When starch granules are embedded in a complex protein matrix, zein limits their accessibility to enzymes and affects the starch digestibility rate. Surprisingly, our results suggest that when enzymes reach starch granules, they digest a greater proportion of the starch when the granules are larger. © 2019 Society of Chemical Industry.

Carotenoid content and antioxidant activity of hexane extracts from selected Croatian corn hybrids.

Carotenoids, which occur naturally in corn grains, have been associated with reduced risk of degenerative diseases. The aim of this research was to measure the carotenoid content of hexane extracts of six commercial high-yield corn hybrids and determine the relationship between carotenoid content and antioxidant activity. Levels of lutein, zeaxanthin, ß-cryptoxanthin and ß-carotene in hexane extracts were determined using HPLC, and antioxidant activity was assayed using the TEAC system based on the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) radical cation (ABTS(+)), and the TBARS system based on a linoleic acid emulsion. Corn hybrids varied in carotenoid content and antioxidant activity in both assays. Lutein and zeaxanthin were the predominant carotenoids; their levels were 15-fold higher than those of ß-cryptoxanthin and ß-carotene. Antioxidant activity in both assays increased linearly with total carotenoid content. Lutein and ß-carotene were the primary contributors to TEAC activity, while lutein, ß-cryptoxanthin and ß-carotene were primary contributors to TBARS activity.

Comparison of spectrophotometric and HPLC methods for determination of carotenoids in foods.

This report is aimed at intra-laboratory and inter-laboratory comparison of the results obtained during spectrophotometric and HPLC analyses of lycopene, ß-carotene and total carotenoids in tomato products and yellow maize flours/grits. Extensive statistical analyses are performed in order to identify the main sources of uncertainties which may occur when using: (i) different techniques/methods/approaches in the same/different laboratories, in various food samples, and (ii) to indicate the facts/conditions under which the biases between results may remain unidentified after applying statistical testing. Our data points to the inertness of t-test to detect significance of differences, particularly at low R values: in general, the higher correlation coefficient, the higher is sensitivity of statistical testing, especially of the paired t-test. Therefore, simple deviation of relationship line slope from unity could be used as additional evaluation parameter. This adds to reliable and objective quality assurance of foods in regard to carotenoids.

Assaying Total Carotenoids in Flours of Corn and Sweetpotato by Laser Photoacoustic Spectroscopy.

This study describes the application of the laser photoacoustic spectroscopy (PAS) for quantification of total carotenoids (TC) in corn flours and sweetpotato flours. Overall, thirty-three different corn flours and nine sweetpotato flours were investigated. All PAS measurements were performed at room temperature using 488-nm argon laser radiation for excitation and mechanical modulation of 9 and 30 Hz. The measurements were repeated within a run and within several days or months. The UV-Vis spectrophotometry was used as the reference method. The concentration range that allows for the reliable analysis of TC spans a region from 1 to 40 mg kg(-1) for corn flours and from 9 to 40 mg kg(-1) for sweetpotato flours. In the case of sweetpotato flours, the quantification may extend even to 240 mg kg(-1) TC. The estimated detection limit values for TC in corn and sweetpotato flours were 0.1 and 0.3 mg kg(-1), respectively. The computed repeatability (n = 3-12) and intermediate precision (n = 6-28) RSD values at 9 and 30 Hz are comparable: 0.1-17.1% and 5.3-14.7% for corn flours as compared with 1.4-9.1% and 4.2-23.0% for sweetpotato flours. Our results show that PAS can be successfully used as a new analytical tool to simply and rapidly screen the flours for their nutritional potential based on the total carotenoid concentration.

Spectrophotometric estimation of total carotenoids in cereal grain products.

Total carotenoids (TC) were determined as a measure of total xanthophylls in grain flours and grits, by new validated spectrophotometric method based on A1cm1%-approach. The general analytical procedure is easily adjustable to different samples, the number of extraction steps depending on TC concentration in the sample. Basically, two methods have been suggested: the rapid one for low-TC samples (white corn, wheat, soybean, sorghum) including one to two extractions, and the one for high-TC samples (yellow corn) needing three to four extractions. Method's accuracy was proven against the reference standard material (102.1±3.9%) and the reference method. Good precision (repeatability and intermediate precision of upto 9% for yellow corn products) and sensitivity with LOD (limit of detection) and LLOQ (lower limit of quantitation) of 0.2 and 0.6 mg kg-1 TC, resp., were estimated. The method was applied to the control of nutritional value of cereal grain products. TC concentration (in mg kg-1) in the samples ranged from 11-23 in yellow corn flours, 0.7-0.9 in white corn flours, 17-22 in yellow corn grits, 1.1-1.3 in wheat flours, 1.6 in wheat grits and 1.5 in sorghum flour, to 0.9-9.9 in soybean flours.