Orientador: Mirna Lucia Gigante / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-04T02:38:22Z (GMT). No. of bitstreams: 1 Henrique_VivianeSoccioMonteiro_D.pdf: 1578287 bytes, checksum: 701e35fa0f63acfe70512383a04328f3 (MD5) Previous issue date: 2004 / Resumo: Os objetivos deste trabalho foram avaliar o comportamento da fase aquosa do queijo Prato durante sua maturação e o efeito do pH sobre a proteólise, a firmeza e a capacidade de derretimento do queijo. Para avaliar o efeito do tempo de maturação sobre a fase aquosa do queijo, após a fabricação, amostras foram aleatoriamente escolhidas diariamente, até o quinto dia de maturação, e avaliadas quanto à quantidade de fase aquosa liberada por centrifugação. A fase aquosa foi avaliada quanto aos teores de sólidos totais, nitrogênio total, frações nitrogenadas e perfil eletroforético. Os resultados indicaram que a fase aquosa liberada por centrifugação diminuiu significativamente durante os primeiros 5 dias de maturação evidenciando um rápido aumento da capacidade de retenção de água da matriz protéica. Através do perfil eletroforético evidenciou-se o aumento de frações caseicas (as1-I-caseína e g-caseína) e de proteínas intactas (b-caseína e as1-caseína) na fase aquosa do queijo com 5 dias de maturação. Estes resultados sugerem que, além da proteólise, o comportamento da fase aquosa do queijo no período inicial da maturação pode ser também responsável pela melhoria da funcionalidade do queijo, uma vez que afeta a hidratação da matriz protéica. Para estudar o efeito do pH sobre a proteólise, a firmeza e a capacidade de derretimento do queijo Prato durante a maturação utilizou-se um método de alteração do pH pós-fabricação. Os queijos utilizados para a troca de pH e posterior avaliação da proteólise foram ralados e os utilizados para a avaliação da firmeza e da capacidade de derretimento foram fatiados (6,5 x 5,0 x 3,0 cm). Em ambos os casos, as amostras foram divididas em 3 porções que foram submetidas aos tratamentos de alteração do pH utilizando-se um dessecador com prateleiras. A primeira porção foi exposta a atmosfera de amônio para aumentar o pH; a segunda porção foi exposta ao vapor de ácido acético para abaixar o pH; a terceira porção serviu de controle. Após a alteração do pH as amostras foram imediatamente embaladas a vácuo e armazenadas a 12 °C. Para avaliar a proteólise amostras foram aleatoriamente escolhidas após 1, 8, 15, 22, 29, 44 e 58 dias de maturação e avaliadas quanto ao pH, sólidos totais, nitrogênio total, nitrogênio solúvel em pH 4,6, nitrogênio solúvel em TCA 12% e perfil eletroforético. A avaliação do efeito do pH sobre a firmeza e a capacidade de derretimento foi realizada após 8 dias de maturação. A melhor condição do teste de derretimento para o queijo Prato foi previamente definida como sendo 130 °C/ 10 minutos. Os resultados indicaram que os índices de extensão e profundidade de maturação aumentaram significativamente ao longo do tempo, porém, aumentaram menos para o pH mais baixo, quando, comparado aos demais tratamentos. O perfil eletroforético evidenciou que nos queijos de menor pH a degradação da *S1 e da *-caseínas ocorreu mais lentamente e menos extensivamente do que nos queijos controle e de mais alto pH. Além disso, observou-se que existe uma correlação linear positiva entre pH e a firmeza dos queijos. Não se observou associação significativa entre o pH e a capacidade de derretimento dos queijos / Abstract: The objectives of this study were to evaluate the evolution of the aqueous phase of Prato cheese in the initial stages of ripening and the independent effect of pH on proteolysis, firmness and melting ability of the cheese. To evaluate the effect of ripening time on the aqueous phase of the cheese after manufacture, samples were randomly taken every day up to the fifth day of ripening and subsequently evaluated for the amount of aqueous phase separated by centrifugation. The aqueous phase was evaluated for the level of total solids, total nitrogen, nitrogen fractions and electrophoretic profile. The results indicated that the aqueous phase separated by centrifugation significantly decreased over the first five days of ripening, thereby evidencing a rapid increase of the water binding capacity of the protein matrix. The electrophoretic profile evidenced an increase of the levels of casein fractions (as1-I-casein and g-casein) and intact proteins (b-casein and as1-casein) in the aqueous phase of cheese after 5 days ripening. These results suggest that, in addition to proteolysis, the evolution of the aqueous phase of cheese in the initial stages of ripening may also contribute to improving the functionality of cheese, as a result of the effect the aqueous phase has on the degree of hydration of the protein matrix. A post-manufacture pH change methods was used to study the independent effect of pH on proteolysis, firmness and melting ability of Prato cheese during ripening. The cheeses submitted to post-manufacture pH change and subsequent evaluation of proteolysis were grated, whereas those used for evaluation of firmness and melting ability were sliced (6,5 x 5,0 x 3,0cm). In both cases, the cheese samples were divided into 3 equal portions and submitted to pH change treatments in a desiccator with shelves. The first portion was exposed to ammonium hydroxide to raise the pH; the second portion was exposed to acetic acid to lower the pH; the third portion was used as control (no treatment). Immediately after the pH change procedure was completed, the samples were vacuum packed and stored at 12°C. To evaluate the effect on proteolysis, randomly selected samples were submitted to analysis after 1, 8, 15, 22, 29, 44 and 58 days ripening and evaluated for pH, total solids, total nitrogen, nitrogen soluble at pH 4,6, nitrogen soluble in 12% trichloroacetic acid (TCA) and electrophoretic profile. Evaluation of the effect of pH on firmness and melting capacity was performed after 8 days ripening. 130°C/10 minutes had previously been determined as the optimal temperature/time test condition for the melting test of Prato cheese. The results indicated that both the ripening extension index and the ripening depth index significantly increased with time, but the increase was less intense in the case of the low pH cheeses. The electrophoretic profile showed that degradation of *S1 and *-caseins occurred at a slower rate and less extensively in the low pH cheeses as compared to the cheese samples of the control and high pH groups. Furthermore, statistical analysis showed that there is a positive linear correlation between pH and the degree of firmness of the cheeses investigated. No significant association was found between pH and the melting ability of the cheeses / Doutorado / Tecnologia de Alimentos / Mestre em Tecnologia de Alimentos

Ph.D. (Biochemistry) / This study consistsof two parts namely: • Phosphoproteins in ripening mango fruit tissue: Effect of y-irradiation and various effectors on protein phosphorylation during the climacteric rise, climacteric peak and post-climacteric stages of ripening. • Protein kinase (EC 2.7.10 and EC 2.7.11) activities in ripening mango fruit tissue: Classification, purification and characterisation.

Orientador: Marcos Omir Marques / Banca: Teresa Cristina Tarlé Pissarra / Banca: Fábio Olivieri de Nóbile / Resumo: Os diversos cultivares de cana-de-açúcar criados a partir de melhoramentos genéticos apresentam diferentes aspectos agroindustriais, gerando além de diferentes remunerações, produtos com qualidades diferenciadas na unidade industrial. Desta maneira, o presente trabalho foi conduzido com o objetivo de comparar cultivares de cana-de-açúcar quanto às suas variáveis tecnológicas, atividades enzimáticas e teores de fosfatos. As amostragens dos colmos de cana foram coletadas nas parcelas experimentais instaladas na Fazenda de Ensino Pesquisa e Extensão da FCAV/UNESP- Jaboticabal, SP. As análises foram realizadas no Laboratório de Tecnologia do Açúcar e Etanol do departamento de Tecnologia. Os cultivares apresentaram diferença em relação aos teores enzimáticos, níveis de fosfatos inorgânicos e características tecnológicas. O cultivar RB867515 obteve os resultados mais satisfatórios do estudo, excetuando-se pela atividade enzimática, onde o cultivar SP81-3250 destacou-se. Todos os genótipos apresentaram teores adequados de fósforo inorgânico para um eficiente processo de clarificação / Abstract: The different cultivars of sugarcane created from genetic improvements have different agroaspects, generating besides different remuneration, products with differentiated qualities in the industrial unit. Thus, this study was conducted in order to compare cultivars of sugarcane as will their technological variables, enzimatic activity and phosphate levels. Sampling of cane stems occurred in Farm Research Education and Extension FCAV / UNESP- Jaboticabal, SP. Analyses were performed in the Sugar and Ethanol Technology Laboratory in technology department of the same university. The cultivars showed differentiation from enzyme levels, inorganic phosphate levels and technological characteristics. The cultivar RB867515 obtained the most satisfactory results of the study, except it is the enzymatic activity, where the SP81-3250 stood out. All genotypes showed inorganic phosphorus levels appropriate for efficient clarification process / Mestre

Os frutos da pitangueira pertencem à família Myrtaceae e podem ser encontrados em três variedades da mesma espécie, reconhecidos de acordo com a cor dos frutos como amarelo, vermelho e roxo. O objetivo deste estudo é caracterizar as três variedades de frutos de pitanga, com relação aos principais carotenoides e compostos fenólicos, e seu comportamento durante o desenvolvimento. Os frutos foram obtidos da região de Campinas (IAC) e fornecidos pela EMBRAPA - (RS). Os extratos metanólico dos frutos foram caracterizados quanto ao conteúdo antocianinas monoméricas, onde somente a variedade roxa, das diferentes plantas e região, apresentou aumento de concentração de antocianinas monoméricas com o desenvolvimento (0,59 a 1,94 mg cy-3-glu eq/g b.s. e 1,43 a 8,47 cy-3-glu eq/g b.s. para o estádio intermediário e maduro, respectivamente. Além disso, a variedade roxa no estádio maduro apresentou maior concentração de fenólicos totais (6,52 a 18,42 mg de AG/g b.s.) quando comparados às outras. O ácido cítrico foi identificado, por CLAE/DAD, como o ácido orgânico majoritário, seguido pelos ácidos succínico e málico, em todas as variedades, com maior concentração no estádio verde. De acordo com a concentração de ácido ascórbico, a pitanga não é uma boa fonte de vitamina C, apresentando valor máximo de 4,0 mg/g b.s no estádio maduro. Os açúcares majoritários encontrados foram a glicose e a frutose. A antocianina majoritária, identificada por LC-ESI-MS/MS, da variedade roxa, no estádio maduro foi a cianidina-3-glicosídeo, com uma variação de 8,05 a 640,53 mg/100g b.s, já o flavonoide majoritário na variedade amarela e vermelha foram miricetina e quercetina em ambas variedades. O carotenoide majoritário identificado por CLAE/DAD, em todas variedades no estádio maduro foi o licopeno, onde a variedade vermelha se destaca pela maior concentração. Dessa forma, o perfil de flavonoides não é alterado com o desenvolvimento, mas é observado uma redução no seu conteúdo nas variedades vermelha e amarela; já a variedade roxa apresenta alteração no perfil de flavonoides, com a expressão de antocianinas no estádio maduro. Por outro lado, o perfil de carotenoides em todas as variedades não sofreu alteração. / The fruits of the pitangueira belong to the family Myrtaceae and can be found in three varieties of the same species, recognized according to the color of the fruits as yellow, red and purple. The aim of this study was characterize the fruits of three pitanga varieties, according to the carotenoids and phenolic compounds composition, and their behavior during ripening. The fruits were obtained from the Campinas region and also provided by EMBRAPA - (RS). Monomeric anthocyaninswere detected only on purple variety, presenting 0.59 to 1.94 mg cy-3-Ο-glu eq/g d.w. and 1.43 to 8.47 cy-3-Ο-glu eq/g d.w.) for the intermediate and mature stages, respectively. In addition, the purple variety at the mature stage had the highest total phenolics concentration (6.52 to 18.42 mg of AG/g d.b.) as compared to other varieties. The citric acid was identified as the major organic acid, followed by succinic and malic acids, in all varieties, with a higher concentration in the green stage. According to the concentration of ascorbic acid, pitanga could not be considered a good source of vitamin C, presenting the highest amount of the 4.0 mg/g d.w. at the mature stage. The major soluble sugars found were glucose and fructose. The major anthocyanin of the purple variety, identified by LC-ESI-MS/MS in the mature stage, was cyanidin-3-Ο-glucoside, ranging from 8.05 to 640.53 mg /100g d.w., whereas the major flavonoids in the yellow and red varieties were myricetin and quercetin. The flavonoid profile was not altered with ripe developing, but a decrease in its content was observed in the red and yellow varieties; on the other hand, the purple variety presented a change in the flavonoid profile, with the expression of anthocyanins in the mature stage. The carotenoids profile in all varieties was the same. The major carotenoid identified by HPLC/DAD, at the mature stage, was lycopene, where the red variety presented the highest concentration.

Oil palm can accumulate up to 90% oil in its mesocarp, the highest level observed in the plant kingdom. In contrast, the closely related date palm accumulates almost exclusively sugars. To gain insight into the mechanisms that lead to such an extreme difference in carbon partitioning, the transcriptome and metabolite content of oil palm and date palm were compared during mesocarp development. Compared with date palm, the high oil content in oil palm was associated with much higher transcript levels for all fatty acid synthesis enzymes, specific plastid transporters, and key enzymes of plastidial carbon metabolism, including phosphofructokinase, pyruvate kinase, and pyruvate dehydrogenase. Transcripts representing an ortholog of the WRI1 transcription factor were 57-fold higher in oil palm relative to date palm and displayed a temporal pattern similar to its target genes. Unexpectedly, despite more than a 100-fold difference in flux to lipids, most enzymes of triacylglycerol assembly were expressed at similar levels in oil palm and date palm. Similarly, transcript levels for all but one cytosolic enzyme of glycolysis were comparable in both species. Together, these data point to synthesis of fatty acids and supply of pyruvate in the plastid, rather than acyl assembly into triacylglycerol, as a major control over the storage of oil in the mesocarp of oil palm. In addition to greatly increasing molecular resources devoted to oil palm and date palm, the combination of temporal and comparative studies illustrates how deep sequencing can provide insights into gene expression patterns of two species that lack genome sequence information.

<p>U&nbsp;radu&nbsp;su&nbsp;ispitane&nbsp;biohemijske&nbsp;promene&nbsp;na&nbsp;plodovima&nbsp;paprike&nbsp;tokom&nbsp;sazrevanja &nbsp;plodova&nbsp;i&nbsp;tokom&nbsp; dozrevanja&nbsp; plodova&nbsp; posle&nbsp; branja.&nbsp; U&nbsp; cilju&nbsp; ispitivanja&nbsp; promena&nbsp; tokom&nbsp; sazrevanja &nbsp;plodovi&nbsp;su&nbsp;uzorkovani&nbsp;u&nbsp;različitim&nbsp;fazama&nbsp;zrelosti&nbsp;tj.&nbsp;kad&nbsp;su&nbsp;plodovi &nbsp;bili&nbsp;zelene,&nbsp;braon,&nbsp;crvene&nbsp;i&nbsp;tamno&nbsp;crvene&nbsp;boje.&nbsp;Svaka&nbsp;od&nbsp;pomenutih&nbsp;grupa&nbsp;zrenja&nbsp;je &nbsp;dozrevana&nbsp;sledećih&nbsp;petnaest&nbsp;dana&nbsp;sa&nbsp;i&nbsp;bez&nbsp;prisustva&nbsp;svetla.&nbsp;Posle&nbsp;perioda&nbsp;dozrevanja &nbsp;plodovi&nbsp;su&nbsp;osu&scaron;eni&nbsp;i&nbsp;samleveni.&nbsp;&nbsp;</p><p>U&nbsp; uzorcima&nbsp; svežih&nbsp; plodova&nbsp; paprika&nbsp; ispitan&nbsp; je&nbsp; sadržaj&nbsp; vode,&nbsp; pepela,&nbsp; ukupnih&nbsp; mono&nbsp; i &nbsp;oligosaharida,&nbsp;mikro&nbsp;i&nbsp;makroelemenata,&nbsp;boja&nbsp;plodova&nbsp;(vizuelnom&nbsp;ocenom&nbsp;i &nbsp;instrumentalnim&nbsp;merenjem),&nbsp;sadržaj&nbsp;pigmenata&nbsp;i&nbsp;sastav&nbsp;etarskih&nbsp;ulja,&nbsp;dok&nbsp;je&nbsp;u&nbsp;suvim&nbsp;uzorcima&nbsp;određena&nbsp;boja, sadržaj&nbsp;mikro&nbsp;i&nbsp;makro&nbsp;elemenata,&nbsp;pigmenata&nbsp;i&nbsp;sastav&nbsp;etarskih ulja. &nbsp;U&nbsp;semenima &nbsp;paprika&nbsp;ispitan&nbsp;je&nbsp;sadržaj&nbsp;vode,&nbsp;pepela,&nbsp;ulja&nbsp;i&nbsp;neophodnih&nbsp;mikro&nbsp;i &nbsp;makro &nbsp;elemenata.&nbsp;</p><p>Dobijeni&nbsp; rezultati&nbsp; pokazuju&nbsp; da&nbsp; se&nbsp; tokom&nbsp; sazrevanja&nbsp; de&scaron;avaju&nbsp; biohemijske &nbsp;promene &nbsp;na&nbsp;plodovima&nbsp; paprika.&nbsp; Povećava&nbsp; se&nbsp; sadržaj&nbsp; suve&nbsp; materije,&nbsp; dolazi&nbsp; do&nbsp; promena&nbsp; u&nbsp; sastavu&nbsp;pigmenata&nbsp;i&nbsp;etarskih&nbsp;ulja.&nbsp;Tokom&nbsp;15&nbsp;dana&nbsp;dozrevanja,&nbsp;ispitani&nbsp;parametri plodova&nbsp;paprika pokazuju&nbsp;da&nbsp;se&nbsp;promene&nbsp;na&nbsp;plodovima&nbsp;nastavljaju&nbsp;i&nbsp;posle&nbsp;ubiranja &nbsp;plodova. &nbsp;U&nbsp;zavisnosti&nbsp;od &nbsp;stepena&nbsp;zrelosti,&nbsp;povećava&nbsp;se&nbsp;sadržaj&nbsp;pigmenta,&nbsp;a&nbsp;menja&nbsp;se&nbsp;i &nbsp;sastav etarskih&nbsp;ulja.&nbsp;</p> / <p>The&nbsp; aim&nbsp; of&nbsp; this&nbsp; study&nbsp; was&nbsp; to&nbsp; investigate&nbsp; biochemical&nbsp; changes&nbsp; of&nbsp; paprika&nbsp; fruits during ripening&nbsp; and&nbsp; postharvest&nbsp; treatments.&nbsp; Fruits&nbsp; were&nbsp; collected&nbsp; in&nbsp; different&nbsp; stages of development i.e. when green, brown, red and deep red color. Each of these&nbsp; color‐type&nbsp; fruits where&nbsp; ripped&nbsp; after&nbsp; harvest&nbsp; (collection)&nbsp; during&nbsp; next&nbsp; fifteen&nbsp; days&nbsp; with&nbsp; or&nbsp; without&nbsp; light.&nbsp; Thereafter, postharvest treatment fruits were dried and milled.</p><p>In samples of fresh paprika fruits the content of water, ash, mono‐ and&nbsp; oligosaharides, micro and macro nutrient,&nbsp; color of fruits (by visual&nbsp; evaluation and&nbsp; instrumental measuring), ASTA value,&nbsp; chlorophyll&nbsp; and&nbsp; carotenoid&nbsp; content,&nbsp; certain&nbsp; constituents&nbsp; of&nbsp; essential&nbsp; oil&nbsp; were determined and activity of peroxidase and &beta;‐glucosidase enzymes, while in dried fruits the color,&nbsp; content&nbsp; of&nbsp; micro&nbsp; and&nbsp; macroelements&nbsp; and&nbsp; composition&nbsp; of&nbsp; essential&nbsp; oils&nbsp; were determined. In seed,&nbsp; the content of water, ash, oil and micro and macroelements were determined.</p><p>Based on the results it could be concluded that, during ripening, the biochemical&nbsp; changes are occurring on paprika fruits. The increase in dry matter content is observ ed along with the changes in pigment and essential oil composition. During the&nbsp; postharvest&nbsp; time, all evaluated parameters indicated that&nbsp; ripening is in progress after the harvest of paprika fruits. Changes in both the&nbsp; pigment and the essential oil content is dependent of a ripening stage.</p>

Low-fat Cheddar cheese flavor is different from full-fat Cheddar cheese and is not acceptable to many consumers. This 2-part experiment was designed to examine effects adjunct cultures have on low-fat Cheddar cheese flavor as determined through descriptive analysis and consumer feedback. In Part 1, low-fat (5%) Cheddar cheese was produced in duplicate, using 6 combinations of DVS850, LH32, CR540, CRL431, Emfour, and CR319 bacterial cultures. Due to a previously observed positive effect by sodium gluconate on low-fat cheese flavor, each replicate was split into treatments of 0.0% and 0.8% sodium gluconate. Each of these treatments was then split into ripening temperature treatments: 6°C for 21 ± 1 wk; or 6°C for 3 wk, 10°C for 8 wk, and 6°C for 10 wk. Cheese was tasted first by an informal panel. The 4 treatment combinations for the control cheese and the CR540 (a Lactococcus lactis ssp. and Lactobacillus ssp. blend) cheese, along with all culture combinations containing sodium gluconate and ripened only at 6°C, were selected for descriptive analysis. Some statistically significant differences in culture treatment were observed. Sodium gluconate addition had a positive influence on flavor while elevated ripening temperature resulted in undesirable flavor notes. Low-fat (5%) Cheddar cheese with the CR540 adjunct with and without sodium gluconate was evaluated in a consumer taste panel with commercial full-fat (33% fat) and commercial reduced-fat (25% fat) Cheddar cheese. The low-fat cheeses were not significantly different from the commercial reduced-fat, indicating comparable cheese. Part 2 involved making Cheddar-like cheese with non-Cheddar adjunct cultures, using the same process as Part 1. Sodium gluconate was again added but elevated ripening temperature was not included. Each treatment was also divided into a sodium treatment, full salt (2%) and reduced salt (1.5%). After 2 mo of storage at 6°C, cheese was tasted by an informal panel and found to be bitter because of the starter culture used. A culture was added to the second replicate of the experiment to reduce bitterness. This adjunct was found to be somewhat effective in reducing bitterness but not entirely. Descriptive analysis was performed on the high salt level treatments for both replicates. Some difference was observed among cultures and sodium gluconate treatments; however, no acceptable cheese was produced due to bitterness in both replicates. Sodium treatments were not analyzed.

No description available.

The object of this investigation was to ripen and dry soybeans in such a way as to prevent the formation of bad taste and odor in the oil. Field run soybeans were treated in specially constructed gas-tight silos through which mixtures of air, carbon dioxide, and ethylene in varying concentrations were recirculated for the purpose of maturing and stabilizing the beans and to prevent peroxidases action, the latter being credited with imparting the offensive odor and taste to the oil and meal obtained by processing the bean. Nine silos were run simultaneously with nine different mixes of gases varying between 90 to 35% ethylene and 10 to 65% carbon dioxide and air. Whole beans were treated for 24 and 48 hours at 24, 37, and 50°C., rolled flat in a roll mill and expressed at 45-60°C. in a Carver hydraulic press at 10,000 lb. per sq. inch. From each sample of beans pressed was taken two samples of oil. One sample was left exposed to the air while the other one was sealed by means of a cap. From the taste and odor tests it was found that whole beans treated with ethylene at 24°C. Gave the best oil, being only slightly better than the oil from the whole beans treated at 37°C. Soybeans, when treated with ethylene and carbon dioxide, absorb varying amounts of the gases, depending on the gas concentration and the water removed. The drying rate of the soybeans by air was considerably less than the drying rate when ethylene and carbon dioxide were used. / Master of Science

Thesis (MSc)--Stellenbosch University, 1964. / ENGLISH ABSTRACT: The influence of manganese sulphate sprays on the yield and ripening of fruit of manganese-deficient Vitis vinifera L. (cv. Pinotage) plants was investigated. Ripening was determined in terms of changes in concentration of the indivi= dual and total sugars and organic acids. Increasing concentrations of manganese sulphate resulted in significant increases in the manganese content of the leaves. The higher levels of manganese were associated with an increase in yield. Ripening, however, was retarded, in that the percentage sugar of the fruit was decreased and titrable acid content increased. The principal sugars present in the fruit were sucrose, glucose, fructose and xylose. Malic and tartaric acids were the main organic acid constituents. Glucose and fructose increased sharply, and sucrose and xylose slightly during ripening of the fruit, whereas malic and tartaric acid de= creased. Glucose, fructose, tartaric and malic acid tended to increase with increasing manganese content. Sucrose and xylose were not appreciably affected. An application of 1% manganese sulphate can be recommend- · ed for manganese deficient vineyards, as it results in an increased yield, in addition to delaying ripening until a more favourable time for handling. Furthermore, the lowered sugar content of the fruit may be advantageous for the pro= duction of dry wines from Pinotage grapes . / AFRIKAANSE OPSOMMING: Die invloed van mangaansulfaatbespuiting op die opbrengs en vrugrypwording van Vitis vinifera L. cv. Pinotage, wat aan ernstige mangaantekorte gely het, is ondersoek. Rypwording is met betrekking tot veranderings in die konsentrasies van totale en indiwiduele suikers en sure bepaal. 2. Toenemende konsentrasies Mnso4 (van O.2% tot l.O%) het n betekenisvolle toename in die mangaangehalte van die blare (van 3 tot 80 d.p.m.) tot gevolg gehad. Die ver= hoogde mangaangehalte het gepaard gegaan met n toe= name in opbrengs, terwyl rypwording vertraag is, deurdat die suikerpersentasie en die titreerbare suurgehalte ver= meerder is in vergelyking met die kontroleplante. 3. Die vernaamste suikers in die vrugte was sukrose, glukose, fruktose en xilose. Glukose en fruktose het vinnig en sukrose en xilose geleidelik toegeneem met die verloop van rypwording. In die ryp vrugte was glukose en fruk= tose oorheersend. Glukose en fruktose was geneig om toe te neem met toenemende mangaangehalte, terwyl sukrose en xilose nie beinvloed is nie. 4. Appelsuur en Wynsteensuur was die oorwegende sure in die vrugte. Beide hierdie sure het gedurende rypwording verminder. Hulle konsentrasies het oor die algemeen toegeneem namate die mangaankonsentrasie verhoog is. 5. Dit is afgelei dat bespuiting met 1.0% MnS04 aanbeveel kan word vir wingerde met mangaantekorte, daar dit n toename in opbrengs, gepaard met 'n vertraging in rypwording tot gevolg gehad het. So 'n vertraging mag moontlik in parstyd voordelig wees. Die verlaagde suikerpersentasie van die vrugte is moontlik gunstig vir die bereiding van droe wyne, waarvoor Pinotage hoofsaaklik gebruik word.