Effect of β-carotene supplementation to prepartum Holstein cows on colostrum quality and calf performance

β-Carotene, a pro-vitamin A carotenoid, acts as an antioxidant, able to scavenge free radicals to prevent oxidative damage. It has also been shown to increase rumen microbial production in vitro. When supplemented prepartum, β-carotene increased colostral fat and protein concentrations. The objective of this experiment was to evaluate the effects of supplementing 700 mg/d β-carotene (BC) daily for 4 wk prepartum on cow performance, colostrum, and performance in subsequent calves. Eighteen multiparous Holstein cows housed in a tiestall barn were blocked by expected calving date and randomly assigned to treatments at 4 wk prepartum. Blood samples were collected 3 times a week for analysis of nonesterified fatty acids, ketones, β-carotene, and IgG. Urine samples were also collected 3 times a week for analysis of creatinine and purine derivatives. Colostrum was collected within 90 min after parturition. Calves were removed from their dams before suckling, weighed within 30 min of birth, and received 4 L of maternal colostrum. Blood samples were collected from calves before colostrum administration (0 h) and at 24 h via jugular venipuncture for analysis of IgG concentration and apparent efficiency of IgG absorption. The 18 calves born were blocked based on treatments of dams. All calves were fed 449 g/d dry matter of milk replacer (20% crude protein, 20% fat) and an 18% crude protein textured starter and water ad libitum at 2 d of age until weaning at 42 d. There were no differences in any blood parameters of cows during the prepartum period. Supplemental BC increased the solids content of colostrum compared with control (22.89% control; 27.75% BC). Calves born from control fed cows had greater efficiency of IgG absorption than those born from BC supplemented cows (52.16% control; 39.50%, BC). Calves born from BC fed cows had greater feed efficiency (average daily gain/dry matter intake) compared with those born from control supplemented cows (0.33 for control; 0.44 for BC). These data indicate that although supplementing β-carotene to cows in the prepartum period negatively affects apparent efficiency of IgG absorption, it improved feed efficiency in calves.     

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.     

Effect of supplementation with algae β-glucans on performance,health, and blood metabolites of Holstein dairy calves

Studies have shown that β-glucans extracted from the cell wall of cereals, algae, and yeasts have been associated with improved immune function. However, it is unknown whether algae β-glucan supplementation affects the performance, blood metabolites, or cell counts of immune cells in dairy calves. The objective of this randomized clinical trial was to evaluate whether supplementation of β-glucans to milk replacer in dairy calves fed 6 L/d improved growth performance and fecal status and altered the blood metabolite profile. In this trial, we enrolled Holstein calves (n = 34) at birth (body weight 36.38 ± 1.33 kg; mean ± standard deviation) to receive, from 1 d of age, either 2 g/d algae β-glucans mixed into 6 L/d of milk replacer (22.4% crude protein and 16.2% fat) or an unsupplemented milk replacer (control). The calves were blocked in pairs according to birth weight, sex, and date of birth (up to 5 d difference). Calves were housed individually, and calf starter (24.7% crude protein and 13.9% neutral detergent fiber) was offered ad libitum based on orts of the previous day until 56 d of age (end of the trial). Body weight was measured weekly, and health checks and daily fecal consistency were evaluated daily in every calf by the same observer. Calves with 2 consecutive days of loose feces that sifted through bedding were considered diarrhea positive. We used a linear mixed effects model to evaluate the effects of β-glucan supplementation fed during the preweaning period on performance (average daily gain), final weight, feed efficiency (FE), white blood cell count, and selected blood metabolites, repeated by time. A generalized linear mixed effects model was also run to evaluate the likelihood of a diarrhea bout in the first 28 d of life, controlling for the calf as the subject with a logistic distribution. We included age, serum total protein at 48 h, and birth weight as covariates. At 56 d, β-glucan-supplemented calves weighed more than control calves (56.3 vs. 51.5 kg). Treatment had no effect on total starter intake, but there was a treatment by age interaction for FE, with greater FE for β-glucan-supplemented calves in wk 3 and 5 of age. There was only a tendency for average daily gain to be greater in supplemented calves than in control calves for the duration of the study. Furthermore, control calves had 14.66 [95% confidence interval (95% CI): 9.87–21.77] times greater odds of having a diarrheal bout than β-glucan-supplemented calves. Control calves had 12.70 (95% CI: 8.82–18.28) times greater odds of having an additional day with an abnormal fecal score compared with β-glucan-supplemented calves, suggesting that supplementation ameliorated diarrhea severity. We found no association of treatment with concentrations of serum total protein, albumin, creatinine, or glucose during the preweaning period. Our findings suggest that dietary supplementation of 2 g/d of algae β-glucans to milk replacer improved fecal status and may affect growth, as evidenced by a higher weaning weight, compared with control calves. Future studies should explore the effect of algae β-glucans on lower-gut physiology and digestibility in dairy calves.     

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.     

Effect of vitamin E supplementation on α-tocopherol and β-carotene concentrations in tissues from pasture- and grain-fed cattle

The effects of dietary vitamin E supplementation of grain-fed cattle on lipid oxidation and meat colour have been extensively investigated, but little attention has been given to pasture-fed cattle where meat is likely to contain naturally high amounts of α-tocopherol and carotenoids. In the work described, we evaluated the effects of pasture-feeding alone and with vitamin E supplementation on tissue levels of anti-oxidants and compared the findings with those obtained for grain-fed cattle with and without supplementation. Sorghum was the major component of the grained-based ration. α-Tocopherol concentrations in plasma, muscle and fat tissues of pasture-fed cattle were not affected by vitamin E supplementation (2500 IU/head/day for 132 days prior to slaughter) while those of grain-fed cattle increased significantly. The α-tocopherol concentrations in the supplemented grain-fed cattle were similar in muscle and liver to pasture-fed animals but were lower in their fat (P<0.05). The major carotenoid present in all tissues studied from pasture-fed was β-carotene and its contents in plasma, liver, fat and muscles were decreased (P<0.05) by supplementation with vitamin E. Carotenoids were essentially absent in grain-fed cattle except for small amounts in liver. The implication of this study for the meat industry is that cattle grazed on good pasture can achieve concentrations of α-tocopherol in muscles and other tissues at least as high as those obtained by supra-nutritional supplementation of grain-fed cattle with vitamin E. However, α-tocopherol supplementation of pasture-fed cattle reduced tissue concentrations of β-carotene, which would reduce carcase fat yellowness and make pasture-fed cattle more acceptable to some Asian markets.     

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 cooking methods on the β-carotene levels of selected plant food materials

In the present study, the β-carotene contents of 14 plant food materials prepared by boiling, steaming, or baking or when they are raw were analyzed and compared. After boiling three pulse species, namely, peas, kidney beans, and dried mung beans, β-carotene contents of peas and kidney beans increased significantly, whereas that of mung beans (dried material) decreased. True retention factors of β-carotene contents in the cooked kidney beans, peas, and mung beans after boiling were 174.2, 128.3, and 91.8%, respectively. After steaming, the β-carotene content of regular millets significantly decreased but that of taros increased, in which the true retention factors were observed with β-carotene contents of 72.4% in the steamed regular millets and 160.9% in the steamed taros. Moreover, β-carotene contents in yellow-fleshed sweet potato (raw: 896.2 μg/100 g) decreased by baking (786.4 μg/100 g) and steaming (steaming: 553.1 μg/100 g). These results suggest that β-carotene contents in the selected plant food materials markedly depend on the cooking method and plant food materials classification.     

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 lipid supplementation on the yield and composition of milk from cows with different β-lactoglobulin phenotypes

Responses to lipid supplementation differ between dairy breeds and genetic lines suggesting nutrition by genotype interactions. β-Lactoglobulin phenotype is associated with changes in yield and composition of milk. The response of cows with different β-lactoglobulin phenotypes to lipid supplementation has not been examined. Furthermore, we examined whether lipid supplementation alters milk protein composition. By using a randomized block design, we fed Holstein cows for 3 wk either a control diet containing 2.8% crude fat (n = 19) or an experimental diet that was supplemented with 4.2% tallow (n = 20). Before randomization, all cows were fed the supplemental tallow diet for at least 2 wk. Dry matter intake, body weight, milk yield, and milk composition were measured in the last week before and during the experimental period. Feeding supplemental tallow increased dry matter intake and yields of milk and milk components, including casein content, without decreasing milk component content or altering milk protein composition. On the low-fat control diet, cows with the β-lactoglobulin allele B had a greater milk and milk component yield than cows with the A allele, whereas no differences by β-lactoglobulin phenotype were observed in cows on the tallow supplement diet. Our results suggest that cows that differ in β-lactoglobulin phenotype respond differently to a low-fat diet and that feeding cows 4.2% of additional tallow increases milk yield without affecting milk component content and milk protein composition.     

Effect of dietary β-carotene supplementation on beef color stability during display of two muscles from Japanese Black steers

Effect of dietary β-carotene supplementation (7500 mg/head/day) for 28 days prior to slaughter on beef color stability during display of M. semimembranosus (SM) and M. longissimus lumborum (LL) from Japanese Black steers was studied. Steak samples from two muscles were over-wrapped with PVC film and displayed under fluorescent lights at 4°C for 12 days. Metmyoglobin percentages of steak samples were determined at days 0, 3, 6, 9 and 12. The β-carotene concentration in both muscles was increased (P<0.001) by dietary β-carotene supplementation. Color display-life of muscles was calculated by the metmyoglobin threshold method based on a threshold value of 20% metmyoglobin. Color display-lives of SM and LL were extended 1.5 and 3 days by dietary β-carotene supplementation, respectively.     

Influence of particle size on lipid digestion and β-carotene bioaccessibility in emulsions and nanoemulsions

The interest in incorporating carotenoids, such as β-carotene, into foods and beverages is growing due to their potential health benefits. However, the poor water-solubility and low bioavailability of carotenoids is currently a challenge to their incorporation into many foods. The aim of this work was to study the influence of particle size on lipid digestion and β-carotene bioaccessibility using corn oil-in-water emulsions with different initial droplet diameters: large (d₄₃ ≈ 23 μm); medium (d₄₃ ≈ 0.4 μm); and small (d₄₃ ≈ 0.2 μm). There was a progressive increase in the mean particle size of all the emulsions as they passed through a simulated gastrointestinal tract (GIT) consisting of mouth, stomach, and small intestine phases, which was attributed to droplet coalescence, flocculation, and digestion. The electrical charge on all the lipid particles became highly negative after passage through the GIT due to accumulation of anionic bile salts, phospholipids, and free fatty acids at their surfaces. The rate and extent of lipid digestion increased with decreasing mean droplet diameter (small ≈ medium ? large), which was attributed to the increase in lipid surface area exposed to pancreatic lipase with decreasing droplet size. There was also an appreciable increase in β-carotene bioaccessibility with decreasing droplet diameter (small > medium > large). These results provide useful information for designing emulsion-based delivery systems for carotenoids for food and pharmaceutical uses.     

Effect of water activity on sugar crystallization and β-carotene stability of freeze-dried mango powder

Storage water activity (a_w) affects the stability of freeze-dried food. The sugar crystallization and storage stability of β-carotene in freeze-dried mango powder was investigated following storage under various relative vapor pressures (11.3-80.9%). Sugar crystallization was revealed by the loss of sorbed water in the water sorption experiment. However, the sorption isotherms showed unclear divergence between the experimental and predicted values. X-ray powder diffraction and scanning electron microscopy were used to confirm the crystallization. The results showed that increased a_w resulted in higher sugar crystallization. The loss of β-carotene was monitored by high-performance liquid chromatography with a diode-array detector and fitted to a first-order reaction. The rate constant decreased as a_w increased up to 0.43, due to the collapse of the mango powder. An increase in the rate constant above this value of a_w coincided with pronounced sugar crystallization. Choosing the appropriate value of a_w for storage can prevent sugar crystallization and enhance β-carotene stability in freeze-dried fruit powder.     

Effects of heat-treated β-lactoglobulin and its aggregates on foaming properties

The effects on foaming properties of the aggregates formed by heating concentrate beta-lactoglobulin solutions (55 mg mL⁻¹, pH 6.8) at 85 °C from 1 to 15 min were investigated. Structural characteristics (size and molecular conformation), hydrophobicity and protein aggregates proportion were also studied. All tested methods pointed at 3 min of heating as a critical time, in terms of conformational changes and aggregation processes. At this time, the most significant conformational changes took place: non-native monomers were present and the greatest amount of dimers and trimers was produced, which was proved with the results of gel densitometry of SDS-PAGE, fluorescence quenching and circular dichroism tests. Foamability and foam stability were both improved by pre-heating the protein. A constant proportion among beta-lactoglobulin species (monomer 51%, dimer 33% and trimer 16%), regardless the protein concentration, led to the same results on foaming properties, confirming the link with structural changes. Aggregates formed by heating beta-lactoglobulin up to 10 min produced more stabilized foams, slowing down disproportionation, because of the formation of stiffer films. The increase in surface hydrophobicity was considered a decisive factor in the improved foamability and hydrophobic interactions improved the foam stability trough the rapid formation of a viscoelastic film.     

Jam processing and storage effects on β-carotene and flavonoids content in grapefruit

Grapefruit phytochemicals (β-carotene and flavonoids) stability after different jam processing was evaluated. Osmotic dehydration, microwave energy and conventional heating techniques have been used to obtain jam. β-Carotene and individual flavonoids were analyzed by HPLC technique. The results showed that jam obtained from osmodehydrated fruit (ODJ) is the only that preserved completely the β-carotene content. All processes of production of jam significantly decreased the content of narirutin (NAT), poncirin (PON), naringenin (NAG) and quercetin (QUER), while naringin (NAR) remained stable. Jams obtained by applying a heat treatment showed significant lower values of NAG and QUER in comparison with ODJ. The jam obtained from osmodehydrated fruit, without being submitted to any heat treatment, showed at the end of storage the highest contents of naringin, hesperidin, neohesperidin, didymin, quercetin, poncirin and the total sum of analysed flavonoids. In general, the phytochemical loss in jams as a consequence of processing was lower than those provoked by storage effect.     

Effect of Sicilian pasture feeding management on content of α-tocopherol and β-carotene in cow milk

This study was performed to evaluate α-tocopherol and β-carotene contents of pasture milk under ordinary Sicilian farming conditions. Fourteen dairy farms were allocated into 2 balanced groups on the basis of cultivated (CULT) or spontaneous (SPO) pasture type feeding. Bulk milk per farm was collected 4 times from February through April at 3-wk intervals. Pasture botanical and diet composition, diet nutritional quality, milk yield and composition were estimated each time. Pasture intake levels were calculated based on feed analyses, hay and concentrate amounts fed, and milk yield and chemical composition. According to pasture intake, the farms were split into low pasture intake (LPI; <29.5% of dry matter) and high pasture intake (HPI; >29.5% of dry matter) groups. Milk samples per farm were analyzed for α-tocopherol and β-carotene contents by HPLC. The SPO group had higher levels of α-tocopherol and β-carotene in milk (0.7 and 0.3 mg/L, respectively) and milk fat (19.0 and 7.5 mg/kg fat, respectively) compared with the CULT group in milk (0.5 and 0.2 mg/L, respectively) and milk fat (14.6 and 4.9 mg/kg, respectively). High pasture intake compared with LPI increased α-tocopherol in milk fat (18.0 and 16.0 mg/kg of fat, respectively). However, only in the SPO (not in CULT), HPI compared with LPI increased milk α-tocopherol (0.8 vs. 0.6 mg/L, respectively), milk β-carotene (0.3 vs. 0.2 mg/L, respectively), and milk fat β-carotene (8.4 vs. 6.6 mg/kg, respectively). Results may be related to the different botanical composition of the respective pasture types and pasture intake. Spontaneous pasture compared with CULT contained a higher mass proportion of Asteraceae, Fabaceae, Cruciferae, Euphorbiaceae, and Malvaceae plants. Milk and milk fat α-tocopherol levels were higher on test-days (TD)-1, TD-2, and TD-4 compared with TD-3. For HPI farms, milk fat β-carotene content was higher on the first 2 TD compared with the last 2 TD. These differences could be related to plant biological stage. On Sicilian dairy farms, the highest milk α-tocopherol and β-carotene contents may be obtained feeding high levels of SPO pasture in the spring.     

Effects of freeze-dried Mitsuokella jalaludinii culture and Natuphos(®) phytase supplementation on the performance and nutrient utilisation of broiler chickens

BACKGROUND: Phytate‐bound phosphorus (P) in poultry diets is poorly available to chickens. Hence exogenous phytase is often added to their diets. Mitsuokella jalaludinii is a rumen bacterial species that produces high phytase activity. In this study the effects of freeze‐dried active M. jalaludinii culture (FD‐AMJC) and Natuphos^® phytase (phytase N) supplementations on the growth performance and nutrient utilisation of broiler chickens fed a low‐available P (aP) diet were evaluated. RESULTS: Supplementation of FD‐AMJC or phytase N to the low‐aP diet improved the feed intake, feed conversion rate, body weight gain, dry matter (DM) digestibility and P, Ca and Mn retention, increased the tibia bone ash content, Ca and P concentrations in tibia DM and P and Zn concentrations in plasma and reduced the P excretion of broiler chickens. However, the feed conversion rate, P and Ca retention, DM digestibility and reduction of P excretion were better with FD‐AMJC than phytase N supplementation. Supplementation of FD‐AMJC to the low‐aP diet also improved the apparent metabolisable energy value of the diet, Cu and Zn retention and crude protein digestibility, but phytase N supplementation did not. CONCLUSION: FD‐AMJC supplementation was more efficient in improving nutrient utilisation and reducing P excretion in chickens than phytase N supplementation. Copyright © 2011 Society of Chemical Industry     

Effects of prepartum 2,4-thiazolidinedione on insulin sensitivity, plasma concentrations of tumor necrosis factor-α and leptin, and adipose tissue gene expression

Administration of peroxisome proliferator-activated receptor gamma (PPARγ) ligands, thiazolidinediones (TZD), to prepartum dairy cattle has been shown to improve dry matter intake and decrease circulating nonesterified fatty acids (NEFA) around the time of calving. The objective of this work was to elucidate mechanisms of TZD action in transition dairy cattle by investigating changes in plasma leptin, tumor necrosis factor-α (TNFα), the revised quantitative insulin sensitivity check index (RQUICKI), and adipose tissue gene expression of leptin, PPARγ, lipoprotein lipase (LPL), and fatty acid synthase (FAS). Multiparous Holstein cows (n = 40) were administered 0, 2.0, or 4.0 mg of TZD/kg of body weight (BW) by intrajugular infusion once daily from 21 d before expected parturition until parturition. Plasma samples collected daily from 22 d before expected parturition through 21 d postpartum were analyzed for glucose, NEFA, and insulin. Plasma samples collected on d −14, −3, −1, 1, 3, 7, 14, and 49 relative to parturition were also analyzed for leptin and TNFα. Adipose tissue was collected on d 7 before expected parturition from a subset of cows, and gene expression was examined via quantitative real-time PCR. A tendency for a treatment by time effect on plasma leptin prepartum was observed such that values were similar on d −14 but cows receiving 2.0 mg/kg of BW of TZD tended to have lower circulating leptin as calving approached. Postpartum leptin tended to be increased linearly (2.3, 2.4, and 2.5 ± 0.1 ng/mL for 0, 2.0, and 4.0 mg/kg treatments, respectively) in cows that received TZD prepartum. Plasma TNFα increased linearly (2.6, 3.7, and 4.0 ± 0.1 pg/mL) in response to TZD treatment and decreased through the first week postpartum. Calculation of RQUICKI 1/[log(glucose) + log(insulin) + log(NEFA)] suggested altered insulin sensitivity in cows administered TZD that may depend on day relative to calving. Administration of TZD increased adipose tissue expression of PPARγ mRNA (11.0, 13.3, and 12.8 ± 1.9). Administration of TZD had a quadratic effect on gene expression of leptin (16.2, 10.7, and 17.4 ± 1.6) and no effect on LPL expression, and expression of FAS was lower for TZD-treated cows than for controls (8.2, 4.2, and 6.1 ± 1.8, respectively). Results imply altered expression and plasma concentrations of leptin, increased plasma TNFα concentrations, and increased expression of PPARγ in adipose tissue as potential mechanisms for the effects of TZD administration on transition dairy cattle.     

Potato lipoxygenase catalysed co-oxidation of β-carotene

Co-oxidation of β-carotene in the presence of linoleic acid was catalysed by potato lipoxygenases. The rate of co-oxidation was dependent on the concentration of both linoleic acid and β-carotene. The maximum rate of co-oxidation occurs at a molar ratio of linoleic acid to β-carotene of 16:1.     

Dihydroactinidiolide from thermal degradation of β-carotene

The formation of dihydroactinidiolide by thermal degradation of β-carotene was studied. A comparison of yields of dihydroactinidiolide in commercial β-carotene and β-carotene derived from crude palm oil was investigated. Thermal degradation of commercial β-carotene promoted the formation of dihydroactinidiolide with the highest yield, 61.21%. Thermal degradation of recovered β-carotene yielded 29.23% of dihydroactinidiolide. The lower recovery of β-carotene was due to the mixture of compounds in the extract. Further investigation indicated some other useful aroma compounds formed from this thermal degradation were β-ionone, 3-oxo-β-ionone, and β-cyclocitral.The outcome provided wide opportunities in utilizing crude palm oil as natural source of β-carotene to produce aroma compound.