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Microbial contamination and survival during storage of bread are a cause of both health concerns and economic losses. Traditional fermentation systems were studied as sources of lactic acid bacteria (LAB) with antagonistic potential against foodborne pathogens and spoilage organisms, with the aim to improve the safety and shelf life of bakery products. The antagonistic activity of four types of buttermilk (BM) products fermented with Lactococcus lactis subsp. lactis was evaluated against a number of pathogenic bacteria to select the best fermented-BM for application as bio-preservatives in bread crumpets, showing up to 9 µg/ml of nisin equivalent antimicrobial activity. These food ingredients could be suitable to be used in crumpet formulations, BM fermented with Lc. lactis subsp. lactis and nisin influenced the quality and shelf life of crumpets; the pH value and firmness of products with fermented BM was lower and the acidity and springiness was higher than for unfermented BM treatment and control withouth additive. The nisin and fermented BM treatment had beneficial effects on the pore size and colour in comparison with the control, and improved microbial shelf life by 2 days. Commercial and traditional sourdough and bread samples (n=18) were collected to assess the diversity of LAB strains and potential properties when applied to dough and bread. DGGE followed by sequencing showed that Lactobacillus was the predominant genus in the studied sourdoughs. Lb. plantarum and Lb. brevis strains accounted for 69% of the 32 isolates, out of which 10 were amylolytic and 12 had proteolytic activity. Most were also good acid producers after 24 h at 30°C. Some LAB strains presented a strong in vitro inhibitory activity against five indicator strains, showing potential as starter cultures to ferment sourdough. In subsequent experiments, the properties of 24 sourdoughs were evaluated, and one of them, fermented with Lb. plantarum (SIN3) yielded low pH value, high lactic acid production, and suitable microbial growth, and was selected for further bread making performance trials. The bread with fast fermentation and high sourdough concentration (FFHSD) had a lower pH, higher acidity and increased the quality attributes with significantly better shelf life comparing to the other treatments during the storage period. Sensory evaluation demonstrated that fast-fermented breads were more acceptable than the slow-fermented counterparts. Bread prepared with high level (18%) of sourdough fast-fermented with the selected culture (SIN3) had a good eating quality and shelf life. The approach of this study is likely to yield feasible improvements of the current methods of preparation of baking goods.

To examine the effect of buttermilk fractions on growth, iron transport, and uptake, Caco-2 cells (human colon adenocarcinoma) were grown in a bicameral chamber. The Caco-2 cell culture system is a useful model to study micronutrient utilization in the human enterocyte, because Caco-2 cells continuously differentiate and form a monolayer, which has high polarity, a well-developed brush border, and a tight junction. Iron bioavailabilty in various milks is very different depending upon milk composition. The fat fraction especially is known to be associated with iron absorption, because the fat fraction has milk fat globule membrane (MFGM), which contains bioactive molecules such as sphingolipids. Composition of buttermilk that was concentrated by 10 K molecular sieving (MS) or by bacterial fermentation (Lactococcus latis PN-l) was reduced in lactose concentration and increased in protein concentration. Percent fat in MS buttermilk was concentrated to two times higher than in the original buttermilk (P < 0.05). Growth of Caco-2 cells with molecular sieved (MS) or fermented (FM) buttermilk in the growth medium was not significantly different. Transport and uptake of 59Fe was performed with/without cold iron (1 mmol/L) by iron-depleted or iron-repleted cells. Molecular sieved or fermented buttermilk and ganglioside or sphingomyelin standards with dimethyl sulfoxide (DMSO) were added to the Hank's balance salt solution (HBSS) in the apical chamber. With cold iron, addition of MS and FM buttermilk (1, 2, or 3 percent) increased 59Fe transport across iron-repleted cells (P < 0.01). Without cold iron, ganglioside depressed 59Fe transport (P < 0.01). Uptake of 59Fe was not significantly affected by buttermilk concentrates; however, more effective uptake was shown across iron-depleted cells. It is not clear from these studies that buttermilk fractions or their components influence iron uptake or transport by Caco-2 cell cultures.

Master of Science / Food Science Institute / Jayendra K. Amamcharla / In recent years, the interest in functional components such as phospholipids (PLs) is increasing as a result of growing awareness of their health benefits. PLs affect several cell functions, such as growth, molecular transport system, memory processing, stress responses, and central nervous system myelination. Many studies have shown that the neutral lipids can be successfully extracted using supercritical carbon dioxide (SCO₂) from different types of foods such as egg, canola, pumpkin seed, fish and dairy powders. It is an alternative method to avoid the use of large quantities organic solvents. The SCO₂ is a safe, environmentally friendly and economical process to extract edible lipids from a variety of matrices. However, a modifier such as ethanol is needed to fractionate PLs due to limited solubility of PLs in SCO₂. The objectives of this study were to optimize the SFE process parameters and to determine the effect of pressure, temperature, and ethanol concentration on the extraction efficiency of PLs from whey protein phospholipid concentrate (WPPC) and buttermilk powder (BMP). Three different batches of WPPC and BMP were obtained from a commercial manufacturer and followed a unique two-step extraction process to isolate PLs from WPPC and BMP. In Step-1, neat supercritical CO₂ was used to remove all the neutral lipids at 414 bar pressure, 60 °C sample temperature, and 5 L/min CO₂ flow rate. The spent solids, the powder left after the first step extraction, were used to extract PLs in the second step. The Step-2 (SCO₂-Ethanol) process was optimized in terms of pressure (350, 414 and 550 bar), temperature (40 °C and 60 °C) and concentration of ethanol (10%, 15% and 20%) as independent factors. All the lipid fractions were analyzed by high performance lipid chromatography (HPLC) and thin layer chromatography (TLC). For WPPC, only ethanol concentration had significant effect (P < 0.05) on the amount of PLs extracted after the Step-2. On the other hand, temperature and ethanol concentration were significantly (P < 0.05) affected the efficiency of SFE for BMP. The optimal processing conditions for WPPC and BMP were 350 bar pressure, 60 °C sample temperature and 15% concentration of ethanol, and 550 bar of pressure, 60 °C sample temperature and 15% concentration of ethanol, respectively. This study allowed obtaining PLs from dairy co-products such as WPPC and BMP as a separate ingredient and this could be useful in nutraceutical and infant formulations as well as different food products formulations.

Properly dried sweet cream buttermilk, because of its high fat and lecithin contents, should make superior ice cream. Its use as a source of serum solids in ice cream. Its use as a source of serum solids in ice cream mix would open an outlet for this butter by-product and would serve the needs of ice cream manufacturers during nonfat dry milk solids shortage and it may make a higher score ice cream. The demand for milk solids shortage and it may make a higher score ice cream. The demand for milk solids has been increasing so rapidly that today the by-products of the dairy industry are being utilized as sources of human food to a much greater extent than before. In past years the greater bulk of creamery buttermilk has been utilized as animal feeds. Attempts are being made to convert more of this by-product into channels of human consumption. As the manufacture of sweet cream butter is increasing at a rapid pace, a larger supply of buttermilk product of high quality which is fit for human consumption is available in the market. Many previous investigators have used buttermilk products as a source of serum solids in ice cream mix with favorable results. The advantage claimed has been that it tends to improve the whipping ability of ice cream mixes and to impart richer flavor to the product. These beneficial qualities have been attributed to the butterfat and the phospholipids, of which lecithin is predominant. The work of Chapman and Supplee shows that buttermilk and cream contins several times as much licithin as skimmilk. The amounts of total phospholipids reported by Holm et al and Wright et al are approximately 1.77 per cent in dry buttermilk and 1.06 per cent in dry skim milk.

Sweet cream liquid buttermilk and skimmed milk ingredients were heat processed and/or exposed to fluorescent light to determine changes in potential flavor compounds. Solid phase microextraction-gas chromatography/flame ionization detection was used to analyze the concentrations of the volatile compounds (2-butanone, 2-pentanone, acetaldehyde, diacetyl, hexanal, methyl sulfide) found in the two components. Pasteurized unoxidized skimmed milk had measurable levels of 2-butanone, acetaldehyde, and diacetyl. Pasteurization of skimmed milk increased concentration of 2-pentanone and methyl sulfide to measurable levels. However only 2-butanone and acetaldehyde were detectable in oxidized skimmed milk. All liquid buttermilk ingredient treatments had measurable concentrations of 2-butanone, 2-pentanone, and acetaldehyde. Pasteurization of unoxidized liquid buttermilk increased the concentration of diacetyl and hexanal to measurable levels whereas oxidized buttermilk, both pasteurized and unpasteurized, had measurable levels of hexanal and methyl sulfide. Nonfat (.3%) dairy beverages were formulated using the same components to determine if the volatiles in liquid buttermilk might enhance the flavor of nonfat milk. Triangle tests and hedonic tests were performed on the nonfat formulations to determine their overall difference and overall acceptance. There was no significant difference between formulations. / Master of Science

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-02T14:23:01Z No. of bitstreams: 2 Dissertação - Renata Teixeira Pfrimer - 2018.pdf: 2774832 bytes, checksum: f22757e6b9629b380e74ba4c8a8782ad (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-02T14:39:42Z (GMT) No. of bitstreams: 2 Dissertação - Renata Teixeira Pfrimer - 2018.pdf: 2774832 bytes, checksum: f22757e6b9629b380e74ba4c8a8782ad (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-02T14:39:42Z (GMT). No. of bitstreams: 2 Dissertação - Renata Teixeira Pfrimer - 2018.pdf: 2774832 bytes, checksum: f22757e6b9629b380e74ba4c8a8782ad (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-28 / Sustainable development has been the transformative purpose of Agenda 2030, implemented by all UN member countries. In order to prevent malnutrition and to use sustainable production and adequate management to protect the planet from degradation, there are opportunities for the development of innovative products. The objective of this study was to develop different formulations of fermented dairy beverage supplemented with buttermilk and flavored with cagaita pulp (Eugenia dysenterica), evaluating its physicochemical, microbiological and sensorial acceptance characteristics. Seven formulations were prepared with different concentrations of milk, whey/buttermilk mixture and cagaita pulp, determined through the simplex centroid design. The formulations were fermented with traditional mixed milk culture composed of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The physico-chemical analyzes reported for the raw material and for the formulations were: pH, acidity, moisture content, ash, protein, lipids, carbohydrates and total energy value. Microbiological analyzes carried out on the formulations were: MPN of Coliforms at 35 ° C, MPN of Coliforms at 45 ° C and Salmonella sp. In the formulations counts of lactic acid bacteria and mold and yeast were determined weekly to determine shelf life. Except formulations F3 and F6, the other formulations showed lactic acid bacteria counts, for fourteen days refrigerated storage, within the standard established by brazilian legislation (6 log10CFU/mL). All fermented dairy drinks presented physical and chemical characteristics within the standards established by brazilian legislation. The whey/buttermilk mixture of the B processing had a higher acidity and a lower pH value in relation to the A and C processing, resulting in the formation of lumps in the formulations F4 and F7 that were manufactured in this processing. The formulations that presented higher milk concentrations were the formulations with lower syneresis and higher sensory scores regarding appearance and consistency. The results indicate that the most cost-benefit formulation is F2, which presents high concentration of co-products, low concentration of pulp and thus a low cost for its manufacture. In addition, he obtained high marks in the attributes oriented in the sensorial analysis and purchase intention. / O desenvolvimento sustentável têm sido o propósito transformador da Agenda 2030, implementada por todos os Países-membros da ONU. Com o intuito de prevenir a má nutrição e utilizar uma produção sustentável e gestão adequada para proteger o planeta da degradação, surgem oportunidades para o desenvolvimento de produtos inovadores. No presente trabalho, objetivou-se desenvolver diferentes formulações de bebida láctea fermentada acrescida de leitelho e saborizada com polpa de cagaita (Eugenia dysenterica), avaliando as características físico-químicas, microbiológicas e aceitação sensorial. Foram elaboradas sete formulações com diferentes concentrações de leite, mistura soro/leitelho e polpa de cagaita, determinadas através do delineamento simplex centroide. As formulações foram fermentadas com cultura mista láctea tradicional composta por Lactobacillus delbrueckii subsp. bulgaricus e Streptococcus thermophilus. As análises físico-químicas da matéria-prima e das formulações foram: pH, acidez, teor de umidade, cinzas, proteína, lipídios, carboidratos e valor energético total. As análises microbiológicas realizadas nas formulações, foram: NMP de Coliformes a 35 °C, NMP de Coliformes a 45 °C e pesquisa de Salmonella sp. Nas formulações foram realizadas, semanalmente, contagens de bactérias ácido lácticas e de bolores e leveduras para determinar a vida útil. Com exceção das formulações F3 e F6, as outras formulações apresentaram contagens de bactérias ácido lácticas, durante quatorze dias de armazenamento refrigerado, dentro do padrão estabelecido pela legislação (6 log10UFC/mL). Todas as bebidas lácteas fermentadas apresentaram características físico-químicas dentro dos padrões estabelecidos pela legislação. A mistura soro/leitelho do processamento B apresentou maior acidez e menor valor de pH em relação aos processamentos A e C, resultando na formação de grumos nas formulações F4 e F7 que foram fabricadas nesse processamento. As formulações que apresentaram maiores concentrações de leite, foram as formulações com menor sinérese e maiores notas em relação à aparência e consistência. Os resultados indicam que a formulação com melhor custo-benefício é a F2 que apresenta alta concentração de co-produtos, baixa concentração de polpa e assim, um custo reduzido para a fabricação. Além disso, obteve altas notas nos atributos avaliados na análise sensorial e intenção de compra.

Les antibiotiques sont fréquemment utilisés dans l’alimentation de la volaille afin de prévenir certaines maladies, dont l’entérite nécrotique, ce qui occasionne l’émergence de souches bactériennes résistantes aux antibiotiques. Une alternative prometteuse est l’utilisation de peptides antimicrobiens (AMPs) comme suppléments alimentaires, tels les AMPs provenant des produits laitiers. L’objectif du projet était de développer une méthode de production d’extraits peptidiques à partir de coproduits de la transformation alimentaire (babeurre, lactoferrine, isolat de protéines de pois), afin de tester si ces extraits peptidiques possédaient une activité antimicrobienne sur les pathogènes spécifiques aviaires suivants : Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli et Staphylococcus aureus. Les protéines ont été mises en suspension dans l’eau (5% p/p) et hydrolysées par la pepsine, 6 heures, pH de 2.5. Les peptides furent récupérés par ultrafiltration (< 10 kDa), puis fractionnés selon leur charge nette : totaux, cationiques, anioniques et non liés. L’effet antimicrobien a été évalué surmicroplaques, par la survie bactérienne en présence de concentrations croissantes d’extraits peptidiques. Les extraits cationiques de babeurre ont démontré une efficacité à une concentration inférieure ou égale à 5 mg/mL; perte de 3 log pour Escherichia coli O78 :H80. En comparaison, la lactoferrine cationique a été efficace à une concentration inférieure ou égale à 0.6 mg/mL; perte de 6 log pour E. coli O78 :H80. Les extraits peptidiques du pois ont démontré une efficacité faible. Cette méthode s’avère prometteuse pour le développement d’une alternative ou d’un complément pour la réduction de l’utilisation des antibiotiques dans l’alimentation de la volaille. / Antibiotics are frequently used in poultry feed in order to prevent certain diseases, including necrotic enteritis, which causes the emergence of bacterial strains resistant to antibiotics. A promising alternative is the use of antimicrobial peptides (AMPs) as dietary supplements, such as AMPs from dairy products. The objective of this project was to develop a production method for the extraction peptides, from co-produced food processing (buttermilk, lactoferrin, pea protein isolates). These peptides were tested for the detection of antimicrobial activity on the following specific poultry pathogens; Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli and Staphylococcus aureus. Proteins were suspended in water (5% w/w) and pepsin hydrolyzed by pepsin for 6 hours at pH 2.5. Peptides were recovered by ultrafiltration (< 10 kDa) and fractionated based on the basis of their ionic charges: total, cationic, anionic and unbound peptides, to specifically target the fractions with antimicrobial activities. Bacterial survival was measured in contact with different peptides concentrations. Cationic buttermilk extracts were effective at a concentration less or equal to 5 mg / mL; loss of 3 log for Escherichia coli O78: H80, compared with lactoferrin which was effective at a concentration less than or equal to 0.6 mg / mL; loss of 6 log for E. coli O78: H80. The peptide extracts from pea showed low efficiency. The use of antimicrobial peptides, from buttermilk, lactoferrin and peas, is promising for the development of an alternative or a complement to reduce antimicrobial use.

The archaeological literature warns against trusting the context of artifacts found within a vertisol due to the constant mixing of sediments caused by the shrink/swell properties of clays. These churning processes were thought to be the defining characteristic of vertisols until only the past few decades. It is now apparent that vertisols vary drastically based on a wide spectrum of variables and are fully capable of forming without churning processes. The Buttermilk Creek Site, Block A represents a prime example of a minimally developed vertisol. In addition, the site itself is a heavily occupied lithic quarry that has been almost continuously inhabited since Clovis and possibly Pre-Clovis times. This thesis takes a detailed look at the sediments and distribution of lithic artifacts from Block A of the Buttermilk Creek site to address the two following research objectives: 1) to determine if the archaeological context within the floodplain sediments at Block A has been disturbed by post-depositional processes, and 2) to identify discrete occupation surfaces within the vertic floodplain sediments at the site. These objectives are addressed using a variety of methods, including: 1) plotting the stratigraphic position of diagnostic artifacts, 2) determining the size distribution of debitage and artifact quantities throughout the floodplain deposits, 3) examining the distribution of cultural versus non-cultural lithic material, 4) recording the presence or absence of heat alteration in the deposits, 5) creating maps showing the degree of fissuring across the site, 6) analyzing differences in patination on artifacts, and 7) analyzing the presence of calcium carbonate on artifacts from all levels. Results from these analyses show that, despite the classification of sediments at Block A as a vertisol, vertical displacement of artifacts is largely absent. Chronologically ordered diagnostic points, consistently size sorted artifacts, and a lack of constant mixing of calcium carbonate throughout the profile suggest that artifacts found as deep as 20 cm below the Clovis-aged horizon represent intact cultural horizons. These oldest components found in Block A may represent some of the earliest known evidence of people in the New World.

Vanderghem Caroline. (2009). La membrane du globule gras du lait : études physico-chimiques et sa valorisation technofonctionnelle dans les babeurres (Thèse de doctorat en Anglais). Gembloux, Belgique, Faculté Universitaire des Sciences Agronomiques de Gembloux. 198p., 14 tabl., 59 fig. Résumé La membrane du globule gras du lait (MGGL) est une structure complexe qui enveloppe, protège et délivre des composants bioactifs et des nutriments dune façon efficace au nouveau-né. Sa structure est unique par rapport à dautres systèmes biologiques de transport de lipides. Lobjectif général de ce travail a été de contribuer à augmenter les connaissances et la compréhension de cet émulsifiant naturel. La première partie de cette thèse concerne létude de la structure de la MGGL. Limportance des protéines membranaires concernant la stabilité et leur disposition dans la MGGL ont été étudiés. Les protéines de la MGGL sont présentes en petite quantité dans le lait et une technique de pré-fractionnement simpose afin de les isoler par rapport aux autres protéines du lait (caséines et protéines du lactosérum). Une technique dextraction qui a été développée dans notre laboratoire a été testée afin disoler la MGGL de la crème laitière. Une analyse détaillée a révélé que cette procédure est très bien adaptée pour lélimination dun maximum de protéines du lait écrémé. Une approche protéomique a été établie et a permis lidentification de protéines majeures de la MFGM ainsi que dautres protéines mineures (GTP-binding proteins, annexins, actin) afin de compléter le protéome. Par la suite, différentes protéases ont été testées en vue dobtenir différents degrés et/ou sélectivité dhydrolyse des protéines de la MGGL. La distribution asymétrique des protéines de la MGGL a été étudiée par une approche basée sur lattaque protéolytique du globule gras natif. Sur base de nos résultats et des données bibliographiques récentes, un nouveau modèle de la structure de la MGGL est proposé. La deuxième partie de cette thèse est consacrée à évaluer les propriétés technofonctionnelles de la MGGL dans les babeurres. Les propriétés interfaciales, moussantes et émulsifiantes du babeurre sont comparées à dautres ingrédients laitiers comme le lait écrémé et le concentré protéique de lactosérum. Nos résultats montrent le bon pouvoir émulsifiant du babeurre en comparaison des autres ingrédients laitiers. Dans les émulsions recombinées, la stabilité envers le crémage a été améliorée et les membranes ont présenté une meilleure résistance face à la coalescence. Les résultats sur la tension interfaciale et les propriétés rhéologiques interfaciales ont été mis en relation avec certaines propriétés des mousses et des émulsions. Vanderghem Caroline. (2009). The milk fat globule membrane: physico-chemical studies and its techno-functional valorisation in buttermilk (Thèse de doctorat). Gembloux, Belgium, Gembloux Agricultural University, 198p., 14 tabl., 59 fig. Summary The milk fat globule membrane (MFGM) is a complex structure that surrounds, protects and delivers bioactive compounds and nutrients in an efficient manner to the neonate. Its structure is unique in relation with any other biological lipid transport system. The overall aim of this work was to contribute to increase the knowledge and comprehension of this natural emulsifier. The first part of this thesis concerned the study of the structure of the MFGM. Membrane proteins were targeted and their importance regarding stability and disposition in the MFGM was studied. MFGM proteins are present at low concentrations in milk and a pre-fractionation of the sample is required in order of MFGM proteins to be visible among other milk proteins (caseins and whey proteins). A mild procedure developed in our laboratory was tested in order to isolate MFGM from cream. Detailed analysis revealed that this procedure is very well suited for the elimination of a maximum of skim milk proteins. A proteomic approach was established and allowed the identification of the most important MFGM proteins and additional minor MFGM proteins for additional completion of the proteome (GTP-binding proteins, annexins, actin). Subsequently, different proteases were screened in an attempt to obtain different degrees and/or selective proteolysis of MFGM proteins. Asymmetric arrangement of MFGM proteins was studied with an approach based on the proteolytic attack on the native fat globule. Based on our results and recent bibliographic data, an updated model of the MFGM structure was proposed. The second part of this thesis was devoted to assess the techno-functional properties of the MFGM in buttermilks. Interfacial, foaming and emulsifying properties of buttermilk were assessed and compared to classic milk ingredients such as skim milk and whey protein concentrate. Our results highlighted that buttermilk possesses good emulsifying power compared to other milk ingredients. In buttermilk recombined emulsions stability towards creaming was improved and the recombined membrane presented a great resistance to coalescence. Results of the interfacial pressure and the interfacial rheological properties were related to some foams and emulsions properties.