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Advisor(s)
Abstract(s)
Um dos principais focos de uma empresa é a sua rentabilidade, utilizando os seus recursos de forma eficiente, isso irá gerar melhores resultados. Sendo a Bel, líder no mercado nacional de queijos, estas preocupações são uma constante na estratégia de posicionamento da empresa, surgindo por isso a necessidade da execução deste projeto. Tendo como foco os grandes volumes de produção, surgiu a possibilidade de trazer mais rentabilidade a uma das matérias primas em uso, o leite, visando alterar a sua temperatura de armazenamento. O objetivo é perceber se, aumentando as temperaturas de armazenamento (9-11˚C, 12-15 horas antes do fabrico), haverá um acréscimo na retenção de proteína do leite no queijo, quando comparado com as temperaturas de armazenamento normalmente utilizadas (2-6˚C). Foram realizados vários ensaios em diferentes fases do ano, condicionando deste modo algumas variáveis devido à sazonalidade inerente ao leite. De forma a cumprir os requisitos de produção, houve, em certas alturas, a necessidade de colmatar a produção com a adição de leite em pó. Esta variável na receita (com e sem adição de leite em pó) foi estudada separadamente de forma a avaliar as possíveis alterações em termos de rendimentos. Os cálculos dos rendimentos foram feitos com base na quantidade de proteína recuperada (proteína do leite recuperada no queijo). Ao longo do estudo houve necessidade de explorar qual o impacto de algumas variáveis ligadas à produção, sobre os rendimentos, e, quantificar a sua influência. De forma a avaliar o efeito destas variáveis sobre os rendimentos foi utilizada a regressão múltipla considerando as seguintes variáveis: tempos de floculação, pH após 5 horas de produção, atrasos dos tempos tecnológicos, rácio de matéria gorda/proteína do leite, a idade do leite, a percentagem de cubas de funcionamento vertical utilizadas e fundamentalmente a temperatura. Conclui-se neste projeto que o aumento da temperatura de armazenamento foi apenas positivamente significativo nos rendimentos em queijo das receitas em que foi adicionado leite em pó. O painel da análise sensorial, concluiu através do teste triangular, que não existiam diferenças entre os produtos que foram expostos a temperaturas de armazenamento mais elevadas (9-11˚C) e a referência (2-6˚C). Na microbiologia, foi elaborado um plano de prevenção e controlo dos psicrotróficos de forma a salvaguardar as alterações que estes microrganismos podem ter sobre o produto final e, foram também detetadas quais as principais variáveis na produção que causam oscilações nos rendimentos do produto em estudo.
One of the main goals in a company is profitability, the more they explore their resources the better the company’s outcomes. Bel is the leader in the Portuguese cheese market hence, their strategic plan is focused on their resources efficiency, for this reason this project emerged. Focusing on the volumes of milk labored per year, after some research, it came out the possibility of increasing yields changing milk storage temperatures. The objective is to study to what extent does rising storage temperature (to 9-11˚C, 12-15 before manufacturing) will affect the protein retention on the cheese yields compared to its current storage temperature (2-6˚C). To explore the effects of temperature on cheese yields the experimentations occurred during different times of the year which attach diverse qualities to the primary resource, the milk. Due to this seasonal variation, addition of powder milk was required to fulfill the production plan. These adjustments will be considered and the two recipes will be separated and compared regarding the yields. The yields were calculated in the perspective of usefulness of the protein (percentage of milk protein that was recovered in cheese). Throughout the study, it became relevant to explore the impact of certain variables such as: duration of the flocculation, pH after 5 hours of production, delays in production, the ratio of fat/protein matter in milk, milk’s age, percentage of vertical working vats used in the production and obviously, the storage temperature of milk. The conclusion of this study was that the rise of storage temperature was only effective in increasing the yields of recipes with addition of powder milk. The sensorial analyses revealed that there was no significate difference between the two products (2-6˚C versus 9- 11˚C; 12-15 hours before manufacturing). Regarding the microbiological analyses, a prevention plan has been developed to control the growth of psycrotrophic bacteria allowing an appropriate forecast of the effects of these bacteria over the product. This thesis also presents a statistical analysis regarding Bel Portugal production data from 2016 and 2017 for the studied product. The analysis focuses on the acknowledgement of the variables that have a statistically significance over the cheese yields.
One of the main goals in a company is profitability, the more they explore their resources the better the company’s outcomes. Bel is the leader in the Portuguese cheese market hence, their strategic plan is focused on their resources efficiency, for this reason this project emerged. Focusing on the volumes of milk labored per year, after some research, it came out the possibility of increasing yields changing milk storage temperatures. The objective is to study to what extent does rising storage temperature (to 9-11˚C, 12-15 before manufacturing) will affect the protein retention on the cheese yields compared to its current storage temperature (2-6˚C). To explore the effects of temperature on cheese yields the experimentations occurred during different times of the year which attach diverse qualities to the primary resource, the milk. Due to this seasonal variation, addition of powder milk was required to fulfill the production plan. These adjustments will be considered and the two recipes will be separated and compared regarding the yields. The yields were calculated in the perspective of usefulness of the protein (percentage of milk protein that was recovered in cheese). Throughout the study, it became relevant to explore the impact of certain variables such as: duration of the flocculation, pH after 5 hours of production, delays in production, the ratio of fat/protein matter in milk, milk’s age, percentage of vertical working vats used in the production and obviously, the storage temperature of milk. The conclusion of this study was that the rise of storage temperature was only effective in increasing the yields of recipes with addition of powder milk. The sensorial analyses revealed that there was no significate difference between the two products (2-6˚C versus 9- 11˚C; 12-15 hours before manufacturing). Regarding the microbiological analyses, a prevention plan has been developed to control the growth of psycrotrophic bacteria allowing an appropriate forecast of the effects of these bacteria over the product. This thesis also presents a statistical analysis regarding Bel Portugal production data from 2016 and 2017 for the studied product. The analysis focuses on the acknowledgement of the variables that have a statistically significance over the cheese yields.
Description
Keywords
Leite Queijo Temperatura Armazenamento Rendimentos Solubilização Caseína Psicrotroficos Enterotoxinas estafilocócicas