Grass pea miso: Development of miso based on a portuguese legume - microbiota and preservation capacity

• Autor(a) principal: Costa, Diogo Miguel Pereira da
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10362/59486
• topic: Fermented foods; miso; grass pea; microbiota; preservation capacity; challenge tests; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Química

Fermented foods are extremely popular nowadays mainly thanks to their health benefits and diversity. One example of a fermented food is miso, a fermented soybean paste very famous in Japan, also considered a functional food and used to make soups or as a seasoning for several dishes. In Japan, miso is made by traditional backslope methods. With the arrival of miso to West-ern countries, more standard, controlled, sustainable and safe processes are needed, starting by switching the soybean by Portuguese legumes (e.g. grass pea) and by developing starters. The aim of this project is to develop an innovative, tastier and safe grass pea miso, using a yeast starter culture and soybean miso as control. The characteristics and evolution of miso were evaluated, based on color and microbiota studies. Results obtained point to an important role of Aspergillus oryzae at the beginning of fer-mentation, and to the maintenance of the viability of yeasts (Candida versatilis) used as a starter along the whole process of miso’s maturation. Also, the obtained product presented good senso-rial characteristics being largely accepted by consumers. The self-preservation capacity of grass pea miso was also evaluated in order to ensure that the product is safe when stored at the consumer’s house and shop shelves. Using challenge tests at several temperatures (4ºC, 25ºC and 37ºC), it was observed a substantial reduction in the pathogenic microorganisms’ population, in most cases leading to its complete elimination. At the temperatures of 37ºC and 25ºC, all the microorganisms were eliminated (except for Bacillus cereus) after 2 days while at 4ºC it takes more than 30 days for them to be eliminated.