The object of this paper is to determine the optimum concentration of sulfur dioxide to be used in the commercial dehydration of the sweet potato by this process. Attention has been given to two aspects of the problem, (1) the effect of sulfur dioxide upon the extraction of water from the sweet potato by mechanical means, and (2) the effect of sulfur dioxide upon the stability of the carotene in the sweet potato over a period of several months.

Experiment 1 A survey on the β-Carotene status of Holstein cows in different feeding systems In order to make meaningful recommendations with regard to β-Carotene supplementation is it necessary to know whether cows are deficient in β-Carotene. The objective of this study was to generate data on the β-Carotene status of Holstein cows under three different feeding systems in South Africa, namely; pasture-based, silage-based and hay-based feeding systems. A survey was conducted amongst 30 farms with 10 farms utilizing each of the three systems. Twenty multiparous cows were randomly selected from each farm. Blood samples were taken from the tail vein and analysed for plasma β-Carotene using the iCheck™, a hand held spectrophotometer (BioAnalyt, GmbH, Germany). Cows were then classified as deficient (< 1.5 mg/L), marginal (1.5 to 3.5 mg/L) or optimal (>3.5 mg/L). The average plasma β-Carotene levels differed between feeding systems and concentrations were 5.53, 2.98 and 1.71 mg/L for the pasture based, hay-based and silage-based feeding systems respectively. There was a wide variation in average plasma β-Carotene concentrations in cows on farms within the different feeding systems. Average values per farm ranged between 3.84 and 10.81 mg/L for the pasture based farms, 0.91 and 5.00 mg/L for the hay-based farms and between 0.78 and 3.38 mg/L for the silage-based farms. Results suggest cows on a pasture based feeding system have optimal β-Carotene status and do not need supplementation. Cows on hay-based systems are marginal and on farm testing is recommended. Cows on silage-based systems are generally deficient and β-Carotene supplementation is recommended. Experiment 2 Effect of prepartum β-Carotene supplementation on the postpartum β-Carotene status of Holstein cows. It has been recommended that cows be supplemented β-Carotene when blood plasma levels are deficient (< 1.5 mg/L) or marginal (< 3.5 mg/L) especially during the transition period which is characterised by low intakes and significant losses of β-Carotene through colostrum. The objective of this trial was to determine to what extent prepartum β-Carotene supplementation could maintain postpartum plasma β-Carotene concentrations above 3.5 mg/L in cows fed a lucerne hay-based TMR. Twenty multiparous Holstein cows were blocked into two groups of ten cows each and were fed either 8kg/d of a control TMR (DM) or the control diet supplemented with 1200mg of ROVIMIX® β-Carotene 10%. The experimental period was from 60d pre-partum until 56d postpartum; however the period of the β-Carotene supplementation for the one group was only from 60d prepartum until calving. Blood samples were collected from the tail vein once per week and analysed for plasma β-Carotene using the iCheck™, a handheld spectrophotometer (BioAnalyt, GmbH, Germany). Average plasma β-Carotene concentrations prepartum were higher (6.15 mg/L) (P < 0.05) for supplemented cows compared to the control cows (3.10 mg/L). For the first 5 weeks postpartum, plasma β-Carotene was higher (P < 0.05) for supplemented cows compared to control cows (3.00 mg/L vs. 1.39 mg/L), from weeks 6 to 9 there were no differences (P > 0.05). Overall the average postpartum plasma β-Carotene values were 1.50 mg/L for the control cows and 2.43 mg/L for the supplemented cows and did not differ. Supplemented cows maintained sufficient β-Carotene concentrations only for the first 2 weeks postpartum and were either marginal or deficient for the rest of the experimental period. Results suggest a minor carryover effect of β-Carotene after prepartum supplementation. / Dissertation (MSc Agric)--University of Pretoria, 2013. / gm2014 / Animal and Wildlife Sciences / unrestricted

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Doctor of Philosophy / Department of Grain Science and Industry / Praveen V. Vadlani / Distillers Dried grain with Solubles (DDGS) is a co-product of grain-based ethanol and is primarily used as livestock feed. With increasing production of DDGS, it is imperative to produce value-added products and/or find new applications of DDGS to help sustain the biofuel industry. Carotenoids are expensive yet essential feed additives. Since animals cannot synthesize carotenoids and animal feeds including DDGS are generally poor in carotenoids, about 30-120 ppm of total carotenoids is added to animal feed to improve animal health. The objectives of this study were to 1) produce carotenoid (astaxanthin and β-carotene)-enriched DDGS by Phaffia rhodozyma and Sporobolomyces roseus monoculture and mixed culture submerged fermentation of whole stillage, 2) optimize fermentation media by response surface methodology (RSM) and mixture design followed by validation, 3) evaluate the nutritional profile of carotenoid-enriched DDGS, 4) improve carotenoid production by the use of precursors, and 5) develop carotenoid-enriched feeds namely, wheat bran, rice bran and soybean products. Carotenoid-enriched DDGS was produced from both monoculture and mixed culture fermentation with yields ranging from 17-233 µg/g. Upon media optimization, astaxanthin and β-carotene yields, especially in P. rhodozyma were enhanced by 177% and 164% to yield 98 and 275 µg/g respectively. Nutrition profiling of the carotenoid-enriched DDGS showed that the secondary fermentation resulted in low fiber, protein and %N and enhanced fat. Fiber was reduced by 77% and 66% by P. rhodozyma and S. roseus respectively, whereas the crude fat increased by 80% in mixed culture fermentation. Additionally, abundant vaccenic acid, a monounsaturated fatty acid was seen in S. roseus and mixed culture fermented DDGS. Vaccenic acid is a precursor of conjugated linolenic acid which is known to confer numerous health benefits. Fermentation of milo DDGS, wheat bran, rice bran and soybean products also resulted in carotenoid enrichment, with the best astaxanthin yield of 80 µg/g in rice bran, and best β-carotene yield of 837 µg/ g in soy flour. Precursors like mevalonic acid, apple pomace and tomato pomace increased carotenoid yield in DDGS and other substrates, with the yield increment depending on the substrate. Mevalonic acid resulted in the best astaxanthin and β-carotene yield increment by 140% and 236% resulting in 220 µg/g and 904 µg/g respectively in corn DDGS. Apple pomace and tomato pomace resulted in 29% carotenoid yield increment. Numerous studies thus far have used cheap agricultural substrates to produce carotenoids especially astaxanthin using P. rhodozyma with the intent of extracting the carotenoids for use in animal feed. However, by fermenting the animal feed directly, carotenoid-enriched feed can be produced without the need for extraction. By this simple yet novel carotenoid value addition, premium feeds or feed blends can be developed. Apart from carotenoid enrichment, low-fiber DDGS can help expand the market base of DDGS for use in non-ruminant feeds. Carotenoid value addition of DDGS can not only help sustain the biofuel industry but can also capture the aquaculture feed base which heavily relies on astaxanthin supplementation.

EXP. 1 Les objectifs étaient d'étudier l'impact potentiel d'un stress thermique dans différentes régions de Thaïlande, de déterminer la répartition mensuelle des vêlages au cours de l'année et de déterminer les sources de variation environnementales de l'intervalle vêlage fécondation (IVF) chez des vaches primipares. Les données climatiques ont été obtenues dans les 25 stations météorologiques provinciales officielles couvrant les 33 provinces inclues dans cette étude. Les données de reproduction ont été fournies par le bureau de " Biotechnology in Livestock Production, Department of Livestock Development, Ministry of Agriculture and Cooperatives ". Ces données concernaient 13 548 lactations de 2004 à 2006. Le plus faible index température-humidité (ITH) a été obtenu en décembre (72) et le plus élevé en avril (80). L'ITH a différé suivant les régions (P<0,0001) et les mois (P<0,0001) et une interaction a été observée entre la région et le mois (P<0,0001). Les vêlages ont été les plus fréquents en septembre et octobre (13,1 - 14,91%) et les moins fréquents en février (4,14 %). L'intervalle moyen vêlage-fécondation était de 151,70 jours. Le mois de vêlage (P<0,0001) et la région (P<0,0001) ont eu un effet sur l'IVF. Les vaches ayant vêlé en février ont eu l'IVF le plus long (219 ± 11 jours) alors que les vaches ayant vêlé en octobre et novembre ont eu l'IVF le plus court (133 ± 7 et 133 ± 7 jours). EXP. 2 Les objectifs étaient 1) d'étudier les effets d'un stress thermique sur le retour de l'activité ovarienne et sur les concentrations plasmatiques en acides gras non estérifiés (AGNE), insulin-like growth factor-1 (IGF-1) et cortisol chez des vaches laitières primipares en post-partum, et 2) d'étudier les effets d'un stress thermique sur la perte embryonnaire de vaches laitières primipares. Cette étude a été réalisée dans une ferme laitière commerciale et comprenait 68 vaches primipares. La proportion de cyclicité ovarienne normale lors d'un stress thermique modéré (SM ; 72 ≤ ITH < 78) était plus élevée qu'en présence d'un stress thermique sévère (SS ; 78 ≤ ITH < 89) (P<0,01). L'intervalle vêlage - 1ère ovulation, l'intervalle vêlage - 1ère IA, l'IVF et la fertilité à la 1ère IA n'étaient pas différents suivant le niveau de stress thermique (SM ou SS). La note d'état corporel et le poids vif n'étaient pas influencés par les groupes d'ITH. Les concentrations plasmatiques en AGNE, IGF-1 et cortisol ne différaient pas entre les groupes d'ITH. La production de lait était différente entre groupes (SM > SS, P=0,03). Ni le nombre, ni les différents types de mortalité embryonnaire n'ont été affectés par le stress thermique. EXP. 3 L'objectif était d'étudier si la supplémentation en béta-carotène pendant le tarissement pouvait 1) augmenter les concentrations sanguines en béta-carotène post-partum 2) améliorer la fonction ovarienne et la progestéronémie 3) améliorer l'involution et la santé utérines 4) améliorer la production laitière et la composition du lait 5) modifier le statut hormonal et métabolique de la vache 6) augmenter la concentration colostrale en IgG 7) modifier le statut hormonal et métabolique et l'activité enzymatique chez le veau nouveau-né. Quarante vaches laitières hautes productrices de race Prim'Holstein ont été utilisées. Un supplément en beta-carotène à été donné individuellement à la moitié des vaches (1g/j ; groupe BC) à partir du tarissement et jusqu'au vêlage. Une supplémentation en béta-carotène pendant le tarissement a augmenté les concentrations en béta-carotène des vaches (P<0,0001). Vingt-huit jours post-partum, le pourcentage de neutrophiles était plus élevé dans le groupe BC que dans le groupe témoin (T) (frottis cervical ; T : 21.0 ± 3.22% vs BC : 9.7 ± 3.14%, P<0,05 et frottis utérin; T: 32.0 ± 3.86% vs BC: 20.9 ± 3.76% ; P<0,05). La concentration plasmatique en hydroxyproline était plus élevée dans le groupe BC que dans le groupe T 21 jours post-partum (T : 15.0 ± 1.33µmol/L vs. BC : 20.8 ± 1.33µmol/L ; P<0,01). La supplémentation en béta-carotène pendant le tarissement n'a pas eu d'effets sur l'activité ovarienne, la progestéronémie, les diamètres du cervix et des cornes utérines, la production laitière et la composition du lait, le statut métabolique et hormonal des vaches, la concentration colostrale en IgG, le statut hormonal et métabolique et l'activité enzymatique du veau nouveau-né.

A anemia causada por deficiência de ferro é a forma mais comum de todas as anemias e afeta grande parcela da população mundial, especialmente o grupo materno-infantil: lactentes, pré-escolares, escolares, gestantes e nutrizes. A carência acarreta atraso no desenvolvimento psicomotor e cognitivo de crianças menores de dois anos, além de diminuição da eficiência da função imune, e agravamento de doenças infecciosas. O presente estudo teve por objetivos avaliar a disponibilidade de ferro em alimentos fontes deste e de vitamina A, ovo (o), cenoura (c) e couve (cv), bem como verificar a interação do ferro com &#945; e ß-caroteno, e com outros interferentes. As misturas foram de ovo com cenoura e ovo com couve em diferentes proporções (1:1), (1:1,5), (1:2), (1:2,5) e (1:3) e também dos 3 alimentos sozinhos, totalizando 13 amostras. As amostras, após pré-preparo e cocção, foram submetidas às análises de composição centesimal, ferro, taninos, ácido fítico, ácido oxálico, &#945;- e &#946;- caroteno e ferro dialisável. Os dados foram submetidos à análise estatística empregando o teste de Tukey, regressão polinomial e correlação, utilizando o software SAS (1996). Os valores para umidade variaram de 83,93 a 95,74 g/100g, apresentando diferenças significativas entre as distintas amostras, assim como para proteínas (0,55 a 7,22g /100g) e extrato etéreo (0,21a 5,94 g/100g). Foi observado que em relação à umidade, extrato etéreo, proteínas, cinzas e &#946;-caroteno houve correlação significativa para o ferro dialisável, sendo que para umidade e &#946;-caroteno essa correlação foi positiva e para os demais componentes foi negativa. Os teores para taninos, fitatos e oxalatos variaram de 0,78 a 1,40 mEqcatequina/g, 0,17 a 0,42 mg/g, e 0,06 a 0,30% respectivamente. A amostra 2 (1o:1,5c) apresentou teores mais elevados de taninos (1,40 mEqcatequina/g), e as amostras 6 (1o:1cv) e 7 (1o:1,5cv) apresentaram teores mais elevados de oxalato e teores de ferro dialisável mais baixo, em relação às outras misturas. O teor de &#945;-caroteno para as amostras contendo cenoura variou de 2.435,27 a 4.609,83 µg/100g. Quanto ao &#946;-caroteno observou-se variações de 2.406,75 a 7.881,55 µg/100g, sendo evidenciado valores mais elevados para as amostras com cenoura. Numericamente, as misturas com maior proporção de cenoura e couve apresentaram os maiores resultados para o ferro dialisável, que variou entre 0,99 a 7,43%, sendo que a amostra 5 (1o:3c) apresentou o melhor resultado, seguida pelas amostras 1, 2, 3, 4, 8, 9 e 10. Pelos resultados obtidos pode-se concluir que as misturas com maior proporção de cenoura e couve aumentaram a disponibilidade do ferro, principalmente pelo maior conteúdo de ß-caroteno. Não houve interferência significativa dos antinutricionais sobre o ferro dialisável, embora os taninos e ácido oxálico atuaram como fatores limitantes quando observados os valores numéricos nas amostras com maiores concentrações de cenoura e couve. O ß-caroteno apresentou correlação positiva significativa com o ferro dialisável, exercendo influência na redução do efeito dos antinutricionais, especialmente dos fitatos, na disponibilidade do ferro, principalmente nas amostras com cenoura. Assim, pode ser recomendada a utilização de misturas de alimentos como ovo e cenoura, sendo que este último deve estar em maiores proporções em refeições destinadas a populações carentes em ferro. / The anemia caused by iron deficiency, is the form more common of all the anemias and it affects large portion of the world population, especially the maternal-infantile group: infants, child-school, children, pregnant woman and nutrizes, carting delay in the development psicomotor and cognitive of smaller children two years old, besides decrease of the efficiency of the immune function, and worsening of infectious diseases. This research aims to estimate the iron availability in food iron sources and vitamin A, egg (e), carrot (c) and cabbage (cb), as well as to verify the interaction of the iron with &#945;, ß-carotene and with other interferents, being mixed the foods in study, resulted 13 food mixtures in different proportions (1:1), (1:1.5), (1:2), (1:2.5) and (1:3) include three food alone. The food mixtures, after prepare and cooking, was submitted the analyses of centesimal composition, levels of iron, tannin, phytic acid, oxalic acid, &#945;, ßcarotene and in vitro iron dialysability. The statistical analysis was determinate by SAS System include polynomial regression and correlation. The values for moisture varied from 83.93 to 95.74 g/100g, showing significant differences among the different mixtures, as well as for proteins (0.55 to 7.22 g/100g) and fat (0.21 to 5.94 g/100g). There was significant correlation with regard to moisture, fat, protein, ash and ß-carotene to in vitro iron dialysability, being positive correlation to moisture and ß-carotene, and negative to other components. The levels of tannins, phytate and oxalates ranged 0.78 to 1.40 mEqcatequina/g, 0.17 to 0.42mg/g and 0.06 to 0.30%, respectively. The mixture 2 (1e:1.5c) showed high levels of tannins (1.40mEqcatequina/g), and the mixtures 6 (1e:1cb) and 7 (1e:1.5cb) high levels of oxalates, and lower levels of in vitro dialysability iron, in relation to the other mixtures. The values for &#945;- carotene to mixtures with carrot ranged 2,435.27 to 4,609.83 µg/100g. With regard to ß-carotene, ranged variations to 2,406.75 from 7,881.55 µg/100g, being observed higher levels for the mixtures with carrot. The numbers showed that the mixtures with larger carrot and cabbage proportion showed the bigger results for the in vitro dialysability iron, ranges to 0.99 from 7.43 %, and the sample 5 (1e:3cb) it presented the bigger value, proceeded by the mixtures 1, 2, 3, 4, 8, 9 and 10. It’s concluded that the mixtures with larger carrot and cabbage proportion increased the iron availability, especially for the largest content of ß-carotene. There was not significant interference of antinutritional in the in vitro iron dialysability, although tannins and oxalates were an inhibitor when observed the numeric values in the mixtures with larger carrot and cabbage concentrations. The ß-carotene showed significant positive correlation with in vitro iron dialysability, increasing influence in the reduction of the antinutritional factors effect, especially phytates, in the iron availability, mainly in the mixtures with carrot. Therefore, the use of food mixtures as egg and carrot can be recommended, and this last one should be in larger proportions in meals destined to lacking populations in iron.

O beta-caroteno é uma substância lipofílica com características nutricionais importantes, mas devido a sua susceptibilidade à degradação, sua ingestão diária pode ficar comprometida. O sistema de encapsulação em micropartículas lipídicas sólidas pode ser uma alternativa para solucionar essa questão, por possuir a propriedade de liberação controlada do bioativo, que aumenta a biodisponibilidade no organismo humano, entre outras qualidades. Existem questões a serem elucidadas acerca da estrutura, modo de preparo e a aplicabilidade de sistemas de micropartículas lipídicas sólidas, e para isso foram testadas formulações utilizando como lipídio sólido a estearina de palma. O tensoativo utilizado neste trabalho foi o isolado proteico de soja, que foi disperso em água deionizada e submetido a tratamento térmico em diferentes condições de pH. Estas dispersões foram caracterizadas quanto ao potencial zeta, tensão interfacial em contato com a estearina de palma, hidrofobicidade superficial, perfil de aminoácidos, caracterização de frações proteicas por meio de eletroforese (SDS-PAGE), calorimetria diferencial de varredura e difratometria em raios-X. A caracterização físico-química dos sistemas de micropartículas foi realizada através de ensaios de distribuição de tamanho de partícula, potencial zeta e concentração de beta-caroteno. Estes ensaios objetivaram avaliar a viabilidade da aplicação na indústria de alimentos, mais especificamente, de sua incorporação em iogurte. Os iogurtes aplicados de micropartículas lipídicas sólidas encapsulando beta-caroteno foram analisados em termos de colorimetria instrumental, análises de pH, acidez, teor de gordura, proteína, densidade, reologia e avaliação de aceitação sensorial. Os resultados obtidos mostraram a possibilidade de estabilização de sistemas com as dispersões de isolado proteico. As dispersões que obtiveram melhor desempenho foram as submetidas a tratamento térmico em pH 12. Os indicaram alta viabilidade de aplicação, especialmente para os sistemas contendo alfa-tocoferol. / Beta-carotene is a hydrophobic bioactive compound with important nutritional value but its high tendency to degradation can reduce its health benefits related to dietary intake. Encapsulation lipid carriers such as solid lipid microparticles (SLM) are feasible alternatives to solve this issue, for example, by increasing its bioavailability. There are many questions about structure, formulation and procedures to be answered and also about its feasibility of application on food products. Aiming at answering some of those questions, this present study tested palm stearin as a solid lipid for the formulations. Soy protein isolate dispersed in deionized water at pH ranging from 3 to 12 were prepared and tested by zeta potential, surface tension in contact with palm stearin, surface hydrophobicity, aminoacids profile, electrophoresis (SDS-PAGE), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. Physicochemical characterization of the SLM systems loaded with beta-carotene was done by particle size, zeta potential and beta-carotene concentration. Aforesaid studies aimed at improving our understanding about the physicochemical stability of those systems and also at evaluating the viability of their incorporation in stirred yoghurt. Different formulations of yoghurt were manufactured and tested by colorimetric analysis, pH, titratable acidity in lactic acid, lipids and protein concentrations, density, rheology and sensory acceptance trials. The results were significantly positive. For the soy protein isolate analysis, the dispersions produced by thermal treatment under alkaline ph (namely, pH 12) had the best performance. Concerning the SLM systems incorporated in yoghurt, further interesting results were found. Yoghurts produced with SLM added to alpha-tocopherol (alfa-tocopherol:beta-carotene concentrations of 1:2 and 1:1) were significantly better from those without alpha-tocopherol regarding colour stability for the observation period of 25 days. Future extensions may focus on enhancing beta-carotene loads to SLM systems as well as on testing the incorporation of SLM systems (or their adaptations) in other food products, particularly those requiring additional colour intensity.