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The purposes of this study are (1) to determine the ascorbic acid content of a variety of fruit juices available in Denton, Texas, during March to July, 1943; (2) to ascertain the loss of ascorbic acid when canned grapefruit, orange, pineapple, and apple juices are opened and stored in the home refrigerator for several days' use; and (3) by means of data obtained, to make recommendations as to the most advantageous ways of using one's "points" in purchasing canned fruit juices for their ascorbic acid value.

Orientador: Fumio Yokoya / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-22T20:33:42Z (GMT). No. of bitstreams: 1 Conti_MariaJosiane_M.pdf: 10300128 bytes, checksum: c571b2db431105550b581c8203ff0630 (MD5) Previous issue date: 2013 / Resumo: O Alicyclobacillus acidoterrestris, é uma bactéria acidotermofílica, não patogênica, de origem ambiental. Este organismo é um potencial agente deteriorante em polpas e sucos de frutas ácidos. Devido à presença de endosporos de elevada resistência térmica, torna-se difícil sua inativação pelos tratamentos térmicos convencionais de pasteutização. Esta pesquisa visou extrair e processar termicamente o suco de seis tipos de frutas tropicais, de caráter ácido (abacaxi, acerola, caju, goiaba, manga e maracujá), e avaliar se estes apresentam condições para que o A. acidoterrestris se desenvolva em sua temperatura ótima (45°C) e também em temperatura de abuso de processamento (35°C), temperatura que favorece o crescimento de microrganismos mesófilos. Além disso, foi analisada a concentração mínima inicial, do microrganismo em estudo, capaz de sobreviver e se desenvolver no suco de manga, aquele que apresentou melhores condições de desenvolvimento na primeira fase do estudo. Neste estudo foi também incluída a análise qualitativa de guaiacol como indicador de deterioração. Foi preparada uma suspensão com a mistura de esporos de quatro cepas de A. acidoterrestris em mesma concentração, padronizada e inoculada nos sucos, previamente extraídos e tratados termicamente, apresentando carga inicial no suco de 102 UFC/mL. O desenvolvimento do microrganismo foi acompanhado através de plaqueamentos em meio de cultura próprio, por até 30 dias, ou até que atingissem uma contagem constante. Ao final, foram avaliados o desenvolvimento máximo da bactéria, em cada suco, na respectiva condição de cultivo, e o período que levou para atingir estes determinados valores. Apenas no suco de caju o pool de bactérias não apresentou desenvolvimento, no prazo máximo estipulado do ensaio (30 dias). O microrganismo apresentou desenvolvimento em todos os demais sucos, alcançando índices de produção de guaiacol e outros subprodutos / Abstract: Alicyclobacillus acidoterrestris is an acidophilic bacterium, nonpathogenic, of environmental origin. This organism is a potential spoiler acid frutits, pulps and juices. Due to the presence of endospores of high heat resistance, it becomes difficult to inactivate it by pasteurization conventional thermal treatment. This research aimed to extract and process thermally the juice of six kinds of tropical fruit, acid character (pineapple, acerola, cashew, guava, mango and passion fruit) and to evaluate if these have conditions for Alicyclobacillus acidoterrestris to develop in optimum temperature (45°C) and also in processing abuse temperature (35°C). Besides, it was analyzed the minimum initial concentration of the microorganism under study, which is able to survive and develop in the mango juice, which presented better conditions of development, according to the first phase of the study. A suspension was prepared with the spores mixture of four strains of A. acidoterrestris in the same concentration, because in preliminary studies it was possible to verify that some strains did not develop in all types of juice. The suspension was standardized and inoculated into the previously extracted and heart treated juices, showing initial concentration of 102 CFU/mL in the juice. The development of the microorganism was accompanied through plating in specific culture medium, for around 30 days or until it reached a constant counting. In the end, bacterium maximum growth was evaluated in each juice, in its respective growing condition and the time it took to achieve these values. The pool of bacteria didn't grow only in the cashew juice. All other juices showed development of the microorganism, reaching production rates of guaiacol and other byproducts, in accordaner with to previous studies / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos

The purpose of this project is to offer a market study of the fruit juices market in France. The aim is to propose not only a comprehensive analysis of the fruit juices market in France, but also a set of recommendations that could be used by managers of fruit juices companies in sustaining a mature market.

Os sulfitos, representados pelo SO2, fazem parte de um importante grupo de aditivos utilizados, há séculos, como conservantes em frutas secas, sucos de frutas, vinhos. No Brasil não existem dados sobre sua utilização pelas indústrias de alimentos e pesquisas sobre o seu consumo pela população. Assim, o objetivo desta pesquisa foi estimar a ingestão de sulfitos em dois grupos de alunos do ensino médio, respectivamente de escola particular e pública. Os dados foram coletados por meio de R24, que permitiu relacionar as fontes de sulfitos presentes na dieta. Para o cálculo do consumo deste aditivo foi utilizado o MPL, definido pela legislação brasileira para cada uma das fontes. Nenhum dos escolares ultrapassou a IDA de 0,70 mg SO2/kg pc/dia, com média de consumo de 0,07 mg SO2/kg pc/dia (p<0,001), sem diferença estatisticamente significante (p = 0,643) entre as escolas particular e pública. Os grandes consumidores (consumo de mais de 50% da IDA, ou seja, 0,35 mg SO2/kg pc/dia, até o limite 0,52 mg SO2/kg pc/dia) representaram 4,5% da amostra pesquisada e alcançaram estes níveis de ingestão devido ao consumo acima de 500 mL/dia de sucos industrializados e similares, e, na escola particular, por associar ao seu consumo bebidas alcoólicas, como cerveja e vinho. / The sulphites, represented for the SO2, are part of an important group of additives, have used for centuries as preservatives in dry fruits, fruit juices, wines. In Brazil there are no data on use of sulphites by the food industry and research on their consumption by population. Thus, the objective of this research was to estimate the ingestion of sulphites in two groups of high school students, one of privative school and another of public school. The data were collected through 24-hour dietary recall, that allowed to relate the sources of sulphites in the diet. For calculation of the consumption of this additive the MPL, stabilished by the Brazilian legislation was used for each sources. None of students exceeded the ADI of 0.70 mg SO2/kg bw/day, with average of consumption of 0.07 mg SO2/kg bw/day (p < 0.001), without statistical difference (p = 0.643) between privative and public school. Heavy consumers (consumption of more than 50% of the ADI, or either, 0.35 mg SO2/kg bw/day, until 0.52 mg SO2/kg bw/dia) represented 4.5% of the searched sample and reached these levels of ingestion due to the consumption above 500 mL/day of fruit industrialized juices, and, in privative school, for associating with its consumption alcoholic beverages, as beer and wine.

La microfiltration est largement utilisée pour la clarification, la stabilisation et la concentration de nombreuses suspensions à base de fruits (jus de fruits, agro-déchets, vin, etc.). Malgré ses divers avantages, la microfiltration présente néanmoins un inconvénient majeur qui est le phénomène de colmatage qui s’installe pendant l’opération de filtration et entraîne une diminution de la perméabilité membranaire. Si de nombreux mécanismes de colmatage (adsorption, blocage de pores, etc.) sont observés pendant la filtration de suspensions polydisperses comme les jus de fruits ou certains coproduits liquides, le dépôt de particules sur la membrane est souvent supposé être le mécanisme limitant. La formation de ce dépôt est fortement dépendante de l’équilibre entre forces convectives (imposées par le flux de perméat), qui attirent les particules de la suspension à proximité de la membrane, et forces de rétrotransport, qui éloignent les particules de la surface membranaire. La stratégie la plus employée pour maitriser le colmatage membranaire par dépôt est la filtration tangentielle qui permet d’imposer de forts cisaillements à la surface membranaire qui favorisent les mécanismes de rétrotransport des particules. Si cette stratégie de maîtrise du colmatage est amplement utilisée à l’échelle industrielle pour la microfiltration des suspensions à base de fruits, elle nécessite des coûts d’investissement et de fonctionnement non négligeables qui limitent son implantation aux industries présentant de fortes capacités de production et d’investissement. Au regard de cela, l’utilisation d’une configuration de filtration à membranes immergées pour la microfiltration de suspensions à base de fruits pourrait être une alternative intéressante. Cette configuration repose sur l’immersion de la membrane (modules plans ou fibres creuses) dans la suspension à filtrer, et est associée à un mode de filtration externe-interne, frontal ou quasi-frontale. Si l’absence de conditions hydrodynamiques intenses au voisinage de la membrane est associée à des flux relativement bas, les nombreux avantages de ce mode opératoire (coûts de fonctionnement réduits, simplicité opérationnelle, forte compacité, etc.) pourraient favoriser son emploi par les petits producteurs de jus de fruits et/ou les industries de valorisation des coproduits présentant des capacités limitées d’investissement et enclins à minimiser leurs couts opérationnels. Ce travail a ainsi étudié pour la première fois la possibilité d’utiliser un tel système pour la microfiltration de suspensions à base de fruits variées (jus de fruits et coproduits vinicoles). Ce travail de thèse a ciblé ainsi plusieurs objectifs : (i) caractériser le potentiel et le comportement colmatant de suspensions à base de fruits, en lien avec les caractéristiques physicochimiques propres à chaque suspension et au regard de leur filtration par membranes immergées, (ii) étudier des performances d’un système de microfiltration de suspensions à base de fruits par membranes immergées, performances en termes de productivité et de sélectivité et enfin (iii) dégager des pistes de réflexion qui conduiraient à une choix pertinent de conditions de filtration (mode immergé ou tangentiel) pour un type de suspension ciblé. Ce travail fournit ainsi des résultats d’identification de paramètres physico-chimiques clefs qui pourraient constituer un premier guide pour le choix de la configuration membranaire la plus adaptée au produit, permettant d’assurer une productivité acceptable lors de la microfiltration de suspensions à base de fruits. / Microfiltration is widely used to ensure clarification, stabilization, and concentration of various fruit-based suspensions (e.g. fruit juices, food by-products, wine). However, the performances of membrane filtration remain highly challenged by membrane fouling. During microfiltration of polydisperse suspensions, such as fruit-based suspensions, membrane fouling is generally associated to the deposition of particles on the membrane layer. This type of fouling is mainly governed by the equilibrium between convective forces (permeate flow), leading particles to flow towards the membrane, and back-transport forces, removing particles away from the membrane surface. The filtration performances depend strongly on this equilibrium, which is mostly governed by the hydrodynamic conditions of the filtration process and the particles size distribution of the suspension. In food industries, cross-flow microfiltration is generally used to limit membrane fouling. In this configuration, high cross-flow velocities are applied in order to enhance the back-transport forces limiting the deposition of foulant materials on the membrane surface. However, this working mode is well known to be highly energy consuming and might not always be relevant depending on the suspension characteristics. In the light of this, using immersed membranes configuration for the microfiltration of fruit-based suspensions might be an interesting alternative, especially for small producers with limiting investment capacity. In this configuration, widely used in other fields, the membranes are immersed in the suspension and filtration is performed in operating conditions close to that of dead-end filtration with limited back-transport forces and low operating costs. However, the performances of this filtration configuration remain little studied for the microfiltration of fruit-based suspensions. In this respect, this work investigated for the first time the possibility of using immersed membranes configuration for the microfiltration of various fruit-based suspensions (fruit juices and winery byproducts). Firstly, a characterization of the fouling potential of various suspensions during their microfiltration using immersed membranes filtration was performed in relation with their physicochemical properties (particle size distribution). Then, this work allowed highlighting the promising performances of immersed membranes configuration when used for the microfiltration of fruit-based suspensions, in terms of productivity and in terms of selectivity (clarification, concentration of bioactive compounds). Finally, it allowed drawing preliminary results about the relation between the physicochemical characteristics of a suspension and its fouling behavior while using (i) immersed membranes filtration or (ii) conventional cross-flow filtration. These results might be of great interest for the identification of relevant physicochemical parameters to predict the usefulness of using high cross-flow velocity to prevent membrane fouling during the microfiltration of fruit-based suspensions.

This thesis describes the development of new adsorptive cathodic stripping voltammetric methods for reliable determination of some trace metals in biological and environmental materials on a glassy carbon mercury film electrode. In particular, the development of these methods involved selection of a suitable complexing agent for the respective metal ion studied, characterization of the electrode processes, investigation of factors affecting the voltammetric response such as concentration and pH of supporting electrolyte, concentration of complexing agent, accumulation potential, accumulation time and electrode rotation rate. Also, organic and inorganic interferences, linear concentration range, and detection limits were carefully considered. Furthermore, the analytical application of the method was demonstrated for each metal in biological and/or environmental materials, after optimization of the sample decomposition procedure. Some conclusions : the results obtained by the AdCSV method for the determination of tin in juices agreed reasonably with those obtained by atomic absorption method; the use of the adsorptive voltammetric technique after dry-ashing and UV treatment of the samples was successfully demonstrated for the determination of vanadium in standard reference materials such as urban particulate matter, peach leaves, apple leaves and bovine liver; and, the use of the adsorptive stripping voltammetric technique, after decomposition of samples by dry-ashing and UV treatment, was successfully demonstrated for the determination of molybdenum in peach leaves, apple leaves and bovine liver samples. / Doctor of Philosophy (PhD)

This dissertation examines the effects of postharvest treatment and processing on biologically active compounds of orange juice, and ??Rio Red?? grapefruit and their ability to prevent chemically induced colon cancer in rat model. The first study evaluated the differences in flavonoid content of commercial ??made from concentrate?? (MFC) orange juices and ??not from concentrate?? (NFC) orange and grapefruit juices. Total flavonoid content of MFC orange juices (53 mg/100 mL; n = 12) was significantly (P &#8804; 0.05) higher than NFC orange juices (36.5 mg/100 mL; n = 14). The second study investigated the ionizing radiation and storage effects on bioactive compounds and quality of ??Rio Red?? grapefruit. Results showed that storage and irradiation significantly (P &#8804; 0.05) affected the bioactive compounds in grapefruit, however, the effect of storage was prominent. The third study examined the influence of irradiation and freeze drying on bioactive compounds of grapefruit. Irradiation of grapefruit prior to freeze drying resulted in enhanced (P &#8804; 0.05) flavonoid content (naringin and narirutin). Freeze drying markedly reduced (P &#8804; 0.05) lycopene content. Freeze drying and irradiation reduced (P &#8804; 0.05) volatile compounds (d-limonene and myrcene), with the exception of ethanol. In the fourth study suppression of colon cancer development in Sprague Dawley rats by natural and irradiated grapefruits and their functional compounds, naringin and limonin, were evaluated.The total number of aberrant crypts (AC; P = 0.02), number of high multiplicity AC foci (ACF; P = 0.01), and proliferative index (P = 0.02) were lower and apoptosis (P = 0.02) was higher in azoxymethane (AOM) injected rats on experimental diets. However, only natural grapefruit and limonin only suppressed AOM induced expansion (P = 0.008) of proliferative zone and also enhanced apoptosis more effectively than other experimental diets indicating that natural grapefruit and limonin may serve as better chemopreventive agents compared to IGFPP and naringin. The present study indicates that postharvest quarantine doses of irradiation slightly alter composition of bioactive compounds and in turn marginally reduce the chemopreventive ability of grapefruit against the promotion stage of colon cancer. These results warrant the necessity of testing the impact of post harvest treatments on fruits and vegetables chemopreventive ability.

Tyrimais įrodyta, kad vynuogių sultys turi teigiamą poveikį mažinant rizikos veiksnius, susijusius su širdies ir kraujagyslių ligomis, dėl vynuogių sultyse esančių fenolinių junginių. Vynuogių sultyse esantys biologiškai aktyvūs junginiai yra stiprūs antioksidantai, kurie slopina kai kurių rūšių vėžio vystymąsi. Darbo tikslas — nustatyti ir palyginti natūralių sulčių, pagamintų iš skirtingų Lietuvoje augančių vynuogių veislių (Vitis vinifera L.) uogų, ir komercinių vynuogių sulčių kokybinius ir kiekybinius rodiklius, įvertinti antioksidacinį aktyvumą. Pasterizuotose vynuogių sultyse nustatytas statistiškai reikšmingai didesnis tankis (p<0,05) nei komercinėse vynuogių sultyse. Komercinėse vynuogių sultyse nustatyti didesni pH reikšmės ir sauso likučio kiekiai. Komercinėse mėlynų vynuogių sultyse spektrofotometriškai nustatytas didžiausias bendras fenolinių junginių ir antocianinų kiekis (p<0,05). Antioksidacinis aktyvumas tiesiogiai koreliavo su biologiškai aktyviais junginiais, bet statistiškai reikšmingai didesnė priklausomybė nustatyta nuo bendro fenolinių junginių kiekio (p<0,01, r = 0,684). / Grape juices have been shown in the study to have beneficial effect on reducing cardiovascular risks, possibly due to the high quantity of phenolics compounds. Bioactive compounds in grape juices are powerful antioxidants, which inhibit the development of some types of cancer. The aim of this research is to determine and compare quality indicators and antioxidant activity of natural grapes juices produced from the different grape species (Vitis vinifera L.) and commercial grapes juices. In pasteurized grape juices were determined statistically significantly higher density (p<0,05) than in commercial grape juices. In commercial grape juices were determined bigger pH value and dry residue levels. Commercial grape juice from blue berries have the biggest content of phenolics compounds and anthocyanins (p<0,05). Antioxidant activity directly correlated with bioactive compounds but statistically higher dependence is from totol phenolics compounds (p<0,01, r = 0,684).

No description available.