Influence of antioxidant spices on the retention of β-carotene in vegetables during domestic cooking processes

Considerable amounts of β-carotene were lost during the two domestic methods of cooking commonly used, namely, pressure cooking and open pan boiling, the loss ranging from 27 to 71% during pressure cooking and 16–67% during boiling for the four vegetables examined in this study. Pressure cooking of green leafy vegetables resulted in a greater retention of this provitamin. In the presence of red gram dhal, which is a common ingredient in the diet, there was an underestimation of β-carotene due to poor extractability. Inclusion of acidulants—tamarind and citric acid-along with these vegetables brought about some changes in the level of retention of β-carotene. The antioxidant spice turmeric generally improved the retention of β-carotene in all four vegetables studied. Onion also had a similar effect. The combinations of acidulants and antioxidant spices also improved the retention of β-carotene during cooking. This effect seemed to be additive in the case of processing of amaranth by boiling.     

Effects of prepartum supplementation of β-carotene on colostrum and calves

Little is known about transfer of dietary β-carotene into colostrum, its absorption by the calf, and its effects on retinol and α-tocopherol in the calf when the dam's dietary vitamin A is adequate. Our objective was to assess the effect of β-carotene supplementation during the close-up dry period on the colostrum and calf. The study was conducted on a large commercial dairy farm in Indiana during early summer of 2015. Ninety-four multiparous Holstein cows were blocked by calving data, parity, and previous production, and then randomly assigned to either control or β-carotene (BC) treatments. While locked in headgates each morning, each cow received a topdress of β-carotene (Rovimix, DSM Nutritional Products, 8 g/d; provided 800 mg β-carotene) or carrier from 21 d before expected calving until calving. Colostrum was collected within 2 h of parturition. Calf blood samples were obtained within 2 h of birth before receiving the dam's colostrum, at 24 h after birth, and at 7 d and 60 d of age. Blood serum was analyzed for β-carotene, retinol, α-tocopherol, and other metabolites and enzymes. Colostrum was analyzed for β-carotene, retinol, α-tocopherol, colorimetry profile, and milk components. Data were analyzed using mixed-effects models in SAS (SAS Institute Inc.). Calf serum β-carotene data were analyzed using the FREQ procedure. Colostrum β-carotene was higher for BC cows. Colostrum from BC cows had increased a* [measures red (positive) to green (negative)] and b* [measures yellow (positive) to blue (negative)] colorimeter values, indicating that β-carotene altered colostrum color toward red and yellow. Supplementation did not affect colostral or calf IgG concentrations. Colostrum color indices were correlated with IgG concentrations as well as concentrations of β-carotene, retinol, and α-tocopherol. Before receiving colostrum, the concentration of β-carotene in calf serum was below the detectable threshold of 0.05 μg/mL. At 24 h of age, the number of calves with detectable β-carotene concentrations increased, with more calves from BC cows (52.1%) having detectable concentrations than calves from cows in the control group (6.1%). No differences in concentrations of retinol or α-tocopherol were observed in calf serum. Supplementation of β-carotene to cows decreased activities of gamma-glutamyl transpeptidase and glutamate dehydrogenase in calf serum. In pregnant cows already receiving adequate vitamin A, supplementation of β-carotene increased concentration of β-carotene in colostrum, altered colostrum color, and increased serum β-carotene in calves at birth.     

Performance of selected emulsifiers and their combinations in the preparation of β-carotene nanodispersions

In this work, the characteristics of β-carotene nanodispersions prepared with sodium caseinate (SC), Tween 20, decaglycerol monolaurate (ML750) and sucrose fatty acid ester (L1695) using solvent displacement technique were compared. The mean particle size of the nanodispersions ranged from 30 nm to 206 nm, depending on the emulsifier used. SC-stabilized nanodispersions had the largest particles size, while those prepared with Tween 20 had the smallest. The mean particle size and size distribution of the nanodispersions generally remained unchanged after 8 weeks of storage time at 4 °C, but the β-carotene content in all nanodispersions decreased over time. The β-carotene in SC-stabilized nanodispersions was the most stable against oxidation among all samples, most likely due to the small specific surface area of the particles, physical barrier of SC protecting the encapsulated β-carotene against free radicals and the antioxidative activity of caseins. The combined effect of SC and ML750 or L1695 on the mean particle size and β-carotene retention was also investigated. Nanodispersions prepared with SC-ML750 or SC-L1695 showed larger mean particle sizes compared to those prepared with ML750 or L1695 alone. However, the stability of β-carotene in these systems was improved owing to the antioxidative activity of SC. This work demonstrated the importance of emulsifier in determining the characteristics and stability of β-carotene nanodispersions.     

Emulsion design for the delivery of β-carotene in complex food systems

β-Carotene has been widely investigated both in the industry and academia, due to its unique bioactive attributes as an antioxidant and pro-vitamin A. Many attempts were made to design delivery systems for β-carotene to improve its dispersant state and chemical stability, and finally to enhance the functionality. Different types of oil-in-water emulsions were proved to be effective delivery systems for lipophilic bioactive ingredients, and intensive studies were performed on β-carotene emulsions in the last decade. Emulsions are thermodynamically unstable, and emulsions with intact structures are preferable in delivering β-carotene during processing and storage. β-Carotene in emulsions with smaller particle size has poor stability, and protein-type emulsifiers and additional antioxidants are effective in protecting β-carotene from degradation. Recent development in the design of protein-polyphenol conjugates has provided a novel approach to improve the stability of β-carotene emulsions. When β-carotene is consumed, its bioaccessibility is highly influenced by the digestion of lipids, and β-carotene in smaller oil droplets containing long-chain fatty acids has a higher bioaccessibility. In order to better deliver β-carotene in complex food products, some novel emulsions with tailor-made structures have been developed, e.g., multilayer emulsions, solid lipid particles, Pickering emulsions. This review summarizes the updated understanding of emulsion-based delivery systems for β-carotene, and how emulsions can be better designed to fulfill the benefits of β-carotene in functional foods.     

Effect of heating on solid β-carotene

The effect of heating on isomerisation and stability of solid β-carotene was investigated, and the products generated by heating were analysed by a number of analytical techniques, including high-performance liquid chromatography (HPLC), UV/VIS-spectroscopy (UV) and gel permeation chromatography (GPC). For the first time, isomerisation of cis- to all-trans-isomer was demonstrated in partly melted solid β-carotene when β-carotene was heated at 90 and 140 °C. Only a few high molecular weight components were detected by GPC when β-carotene was heated in a nitrogen environment. In contrast, more high molecular weight polymers, as well as low molecular fragments, were produced when β-carotene was heated and exposed to air, suggesting that polymerisation was one of the dominant side-reactions of β-carotene change, in addition to degradation.     

Effects of prepartum supplementation of β-carotene in Holstein cows

Whether supplemental dietary β-carotene affects periparturient cows and vitamins A and E in cows when dietary vitamin A is adequate remains uncertain. Our objective was to assess the effect of β-carotene supplementation during the close-up dry period in a herd with adequate status of vitamins A and E but low in β-carotene. The study was conducted on a large commercial dairy farm in Indiana during early summer of 2015. Ninety-four multiparous Holstein cows were assigned to either control (CON; n = 47) or β-carotene (BC; n = 47) treatments. When locked in headgates each morning, each cow received a topdress of β-carotene (Rovimix, 8 g/d; provided 800 mg of β-carotene) or carrier from 21 d before expected calving until calving. Blood samples were collected at 21 ± 1 d (mean ± standard deviation) before expected calving (before treatments began), 7 ± 1 d before calving, immediately following parturition, and 7 ± 1 d postpartum. Blood serum was analyzed for vitamins A and E, β-carotene, cholesterol, and other metabolites and enzymes. Data were analyzed using the MIXED procedure in SAS (SAS Institute Inc.). Cows had low β-carotene concentrations (0.85 μg/mL) in blood serum before treatments began. Compared with CON cows, BC cows had higher overall mean concentrations of β-carotene (2.87 μg/mL vs. 0.73 μg/mL) and retinol (165 vs. 143 ng/mL). Cows fed BC had lower α-tocopherol in serum than cows fed CON (2.26 vs. 2.46 µg/mL). Cows fed BC had lower peak milk than cows fed CON (50.9 vs. 55.3), but total lactation milk yield did not differ significantly. No effects of BC were observed on days to conception (100 d) or times bred (2.4). Treatments did not affect incidences of ketosis, retained placenta, displaced abomasum, off feed, lameness, footrot, mastitis, or metritis. In conclusion, in pregnant cows already receiving adequate vitamin A but with low serum β-carotene concentration, supplementation of β-carotene increased concentrations of β-carotene and vitamin A in blood serum, but did not affect production, reproduction, or health.     

Comparative study on the levels of carotenoids lutein,zeaxanthin and β-carotene in Indian spices of nutritional and medicinal importance

The carotenoid levels in Indian spices of nutritional and medicinal importance were determined using high performance liquid chromatography. Lutein (L) and zeaxanthin (Z) levels (mg/100 g dry wt) in curry leaves (27.34), spearmint (18.0), green chilli (13.74), coriander leaves (9.92) and mustard seeds (1.2) were higher (2–22-fold) than mace, anise seeds, onion, fenugreek seeds and carum seeds (0.62 and 0.85) whilst their levels in cumin seeds, black pepper, green cardamom and coriander seeds were in the range of 0.32–0.47. β-Carotene (mg/100 g dry wt) was higher in coriander leaves (67.5), green chilli (9.06), curry leaves (8.95) and spearmint (7.5) than black cardamom (0.22) and coriander seeds (0.22), respectively. Neoxanthin, violaxanthin and α-carotene levels were also discussed. Spices analysed are a better source of L + Z than β-carotene (except for coriander leaves). Usage of spices as an adjuvant in food preparations also provides L + Z as antioxidants.     

Effects of α-tocopherol, β-carotene and ascorbyl palmitate on oxidative stability of butter oil triacylglycerols

Butter oil triacylglycerols (BO-TAGs), free of antioxidants, including β-carotene, were obtained via sequential treatments with activated carbon (AC) adsorption and alumina column chromatography. α-Tocopherol, β-carotene and ascorbyl palmitate (AP) were added to BO-TAGs, individually, or in different combinations. An accelerated oven-oxidation test was carried out at 60 °C to determine the most effective dosages of the antioxidants. Among the antioxidants evaluated, α-tocopherol was found to be the most effective, at the concentration of 50 μg/g. To determine the possible synergism between the antioxidants, binary or ternary combinations of α-tocopherol, β-carotene and AP were added to BO-TAGs at concentrations of 50, 5, and 50 μg/g, respectively. Ternary combinations of these antioxidants were significantly better in retarding oxidation than were binary blends of α-tocopherol with β-carotene or AP. However, a prooxidant effect was observed, especially when β-carotene and AP were used individually or in binary combination.     

Effects of processing and packaging on vitamin C and β-carotene content of ready-to-use (RTU) vegetables

High pressure liquid chromatographic methods were used for measurement of the concentration of vitamin C and β-carotene in broccoli and green pepper. The effects of processing, packaging and storage on the levels of these nutrients in both unprocessed and processed ready-to-use (RTU) vegetables were determined. Systems investigated included: (a) unpacked and pillow packaged broccoli, and (b) unpacked, pillow, partial vacuum, and total vacuum packaged green pepper. There was a statistically significant decrease in vitamin C over a 10 day storage period of unpacked and packaged vegetables including all four packaging systems (P<0.001, overall average decrease of 11%). The overall loss of β-carotene during the 10 day storage period was not statistically significant (P=0.14). Although there was a significant loss in vitamin C during storage, in most cases there was no difference in loss of vitamin C or β-carotene between the processed and unprocessed vegetables, and the packaging systems.     

Effects of parboiling,storage and cooking on the levels of tocopherols,tocotrienols and γ-oryzanol in brown rice (Oryza sativa L.)

Vitamin E and γ-oryzanol display a wide range of biological activities including hypocholesterolemic, anti-inflammatory and antioxidant activities. Although white rice is far more popular worldwide, consumption of brown rice is increasing, partially on account of the presence of bioactive compounds; however, the effects of parboiling, storage and cooking on them are not well-characterized. The effects of parboiling and a 6-month storage period on the contents of vitamin E and γ-oryzanol in three brown rice cultivars grown in three different locations in Brazil were investigated. Also, their levels in branded non-parboiled and parboiled brown rice were monitored before and after cooking. Vitamin E homologues and γ-oryzanol were separated by RP-HPLC equipped with PDA and fluorescence detectors. The average levels of total tocols and γ-oryzanol in the raw brown rice cultivars studied were 25 and 188 mg/kg, respectively. Of the vitamin E homologues, γ-tocotrienol contributed with 74% of total tocols, followed by α-tocopherol, α-tocotrienol and γ-tocopherol in minor quantities. The combined processes, parboiling, storage and cooking, led to an approximate 90% reduction in tocols and only γ-tocotrienol was detectable after any of the processes. Parboiling followed by storage resulted in an approximate 40% loss of γ-oryzanol. Cooking had almost no further effect over γ-oryzanol levels in parboiled rice previously stored for 6 months.     

Ohmic cooking of whole turkey meat – Effect of rapid ohmic heating on selected product parameters

Intact turkey meat was cooked using low temperature long time (LTLT) and high temperature short time (HTST) protocols in a combined ohmic/convection system and compared to conventional (CONV) steam cooking. Both ohmic protocols gave a significantly lighter (p < 0.05) and a more uniform colour vs. CONV, while no significant differences (p ? 0.05) were found in texture profile analysis attributes between LTLT and CONV though HTST showed significantly higher attributes (p < 0.05). Cook loss was significantly (p < 0.05) different between treatments (25.2%, 27.9% and 31.3% for LTLT, CONV and HTST). Sensory studies largely confirmed these observations. Cook values (p < 0.05) were lowest for LTLT (4.0) followed by HTST (5.4) and control (8.5). Lipid oxidation and sulphur-flavour-compound development (measured over 7 days) were higher for conventional than ohmic treatments. Overall, these results demonstrate considerable industrial potential for ohmic heating, yielding high quality products with an 8–15-fold reduction in cooking time.     

Multi-analyte methods for the detection of photoinitiators and amine synergists in food contact materials and foodstuffs – Part I: HPLC-DAD screening of materials

The objective of this work was to develop a HPLC-DAD method suitable for the screening of food contact materials for a total of 63 monomeric and polymeric photoinitiators and amine synergists. Such multi-analyte methods are worthwhile for official control laboratories, where normally no information about the composition of the applied inks or varnishes on the printed or lacquered materials is available and thus target analyses are not feasible. The polymeric analytes were each separated in a multitude of substance peaks, which largely overlaid those of the other compounds. Thus, for 13 polymeric photoinitiators and amine synergists a hydrolysis method was developed that reduced the number of ultraviolet (UV) detectable peaks to only one. This allowed easier identification and – preliminary – semi-quantification of these polymeric substances with adequate limits of detection. The remaining 50 photoinitiators and amine synergists were combined in one HPLC-DAD method. But since many of these substances are structurally related, partly retention times and spectra did not differ significantly. Thus selectivity was enhanced by preparing a database containing all spectra and retention times of the investigated compounds. Furthermore, the retention times of those 50 substances were calculated relative to two internal standards to overcome variances of retention from run to run or due to matrix effects. The developed method was tested for the analysis of food contact materials. Extractions of these were performed with acetonitrile and partially the extracts were subsequently concentrated in a steam of nitrogen. Limits of detection of photoinitiators and amine synergists in concentrated packaging extracts were in the range between 0.02 and 5.5 µg dm^?2.     

Impact of whey protein – Beet pectin conjugation on the physicochemical stability of β-carotene emulsions

The aim of the present study was to investigate the impact of whey protein isolate (WPI)-beet pectin conjugation on the physical and chemical properties of oil-in-water emulsions incorporating β-carotene within the oil droplets. Covalent coupling of WPI to beet pectin was achieved by dry heating of WPI-beet pectin mixtures of different weight ratios at 80, 90, 100 °C and 79% relative humidity for incubation times ranging from 1 to 9 h. It was confirmed by SDS-polyacrylamide gel electrophoresis that WPI covalently linked to beet pectin. The physical and chemical stability of β-carotene emulsions was characterized by droplet size and distribution, transmission profiles using novel centrifugal sedimentation technique, microstructure and β-carotene degradation during the storage. Compared with those stabilized by WPI alone and unheated WPI-beet pectin mixtures, β-carotene emulsions stabilized by WPI-beet pectin conjugates had much smaller droplet sizes, more homogenous droplet size distribution, less change in centrifugal transmission profiles and obviously improved freeze–thaw stability, indicating a very substantial improvement in the physical stability. Rheological analysis exhibited that emulsions stabilized by WPI-beet pectin conjugates changed from a shear thinning to more like Newtonian liquid compared those with WPI alone and unheated WPI-beet pectin mixtures. Degradation of β-carotene in emulsion during storage was more obviously retarded by WPI-beet pectin conjugate than WPI and unheated WPI-beet pectin mixture, probably due to a thicker and denser interfacial layer in emulsion droplets. These results implied that protein–polysaccharide conjugates were able to improve the physical stability of β-carotene emulsion and inhibit the deterioration of β-carotene in oil-in-water emulsions.     

Impact of selected factors – Cultivar,storage, cooking and baking on the content of anthocyanins in coloured-flesh potatoes

The impact of selected factors – cultivar, storage, cooking and baking on the content of total anthocyanins (TAC) in coloured-flesh potato cultivars has been studied. TAC ranged from 248.5 to 2257.8 mg kg⁻¹ dry matter (DM). TAC difference between cultivars was statistically significant. Cold storage (4 °C) influenced TAC differentially. In the Violette and Highland Burgundy Red cultivars TAC increased by 18.5% and 12.1% respectively, and in the Valfi cultivar it decreased by 33.9%. Baking increased TAC 3.34 times whereas cooking in boiled water increased it 4.22 times. Correlation between antioxidant activity (AOA) and TAC (r² = 0.659) has been found. The Violette, Vitelotte and Highland Burgundy Red cultivars with the highest TAC showed high AOA and the Shetland Black cultivar and the cultivars Salad Blue and Blue Congo with a “marbled” texture showed the lowest TAC and AOA. Individual anthocyanidins are fingerprints of colour-fleshed potato cultivars.     

Effect of plant polyphenols on the formation of advanced glycation end products from β-lactoglobulin

Dietary exposure to advanced glycation end products (AGEs) formed from proteins and reducing sugars is of increasing concern to human health. AGEs may form in protein-based powders containing sugars for instant beverages during drying and storage of the product. Chlorogenic acid, a plant phenol characteristic of coffee, was found to protect against the formation of AGEs at a concentration of 50mM during heating of β-lactoglobulin in the presence of glucose as a reducing sugar in 30% aqueous ethanol at 70°C. Epicatechin, a plant phenol characteristic of green tea, had no similar effect for the equivalent concentration of phenol on the formation of AGEs. Immunochemical detection (ELISA) using polyclonal antibodies raised against AGEs showed a dose-dependent effect of protection by chlorogenic acid on AGE formation and is recommended for routine quality control of sugar containing milk-based powders for instant beverages.     

Influence of β-carotene-rich vegetables on the bioaccessibility of zinc and iron from food grains

Widespread deficiencies of iron and zinc, commonly found in populations dependent on plant foods, necessitate food-based strategies to maximise their bioavailability from plant foods. In this study, β-carotene-rich vegetables were evaluated for their effects on the bioaccessibility of iron and zinc from cereals and pulses by employing a simulated gastrointestinal digestion procedure involving equilibrium dialysis. Addition of carrot or amaranth (2.5 g and 5 g per 10 g of grain) significantly enhanced the bioaccessibility of iron and zinc from the food grains, the percent increase being 13.8–86.2 in the case of carrot and 11–193% in the case of amaranth. Pure β-carotene added at an equivalent level also enhanced the bioaccessibility of iron (19.6–102% increase) and zinc (16.5–118.0% increase) from the cereals examined. This is the first report on the beneficial influence of β-carotene on iron and zinc bioaccessibilities.     

Effects of Gac aril microwave processing conditions on oil extraction efficiency,and β-carotene and lycopene contents

The effects of Gac oil extraction conditions including microwave power, microwave time, steaming time and hydraulic pressure on extraction efficiency (EE), and β-carotene and lycopene contents were studied. It was found that the EE, and β-carotene and lycopene contents could be enhanced by suitable extraction conditions. Microwave drying was found to be better than air drying for pretreatment. Moisture content after drying and steaming between 8% and 11% (wt/wt) were best for pressing. Results showed that the most suitable conditions for Gac oil extraction from 900 g samples were microwave power of 630 W, microwave time of 65 min, steaming time of 20 min and hydraulic pressure of 170 kg/cm². Under these conditions, the highest EE of 93% was achieved while Gac oil contained the highest content of β-carotene and lycopene at 140 and 414 mg/100 mL, respectively.