Simultaneous prediction of acidity parameters (pH and titratable acidity) in Kefir using near infrared reflectance spectroscopy

Sensor systems for bacterial reactors: A new flavin-phenol composite film for the in situ voltammetric measurement of pH

“…The production and consumption of kefir beverages has a long history spanning hundreds of years with the probiotic nature of the milk ascribed to numerous health benefits which have been extensively reviewed [28][29][30][31][32][33][34][35][36]. Cow milk is the traditional feedstock but milk from sheep, buffalo, coconut, rice and soy sources, amongst others, have also been used.…”

“…Cow milk is the traditional feedstock but milk from sheep, buffalo, coconut, rice and soy sources, amongst others, have also been used. Irrespective of source factors (species, geography, feed and season) and processing conditions (pH regulation, temperature, fermentation time) that can influence the nutritional composition of the product and overall flavour [33,36], the underlying taste is usually characterised by a tart/acidic tang. The latter arises from the microbial production of lactic acid during the fermentation process [28].…”

“…The latter arises from the microbial production of lactic acid during the fermentation process [28]. The degree of acidic aftertaste can affect its palatability and hence monitoring the pH during production can enable greater control over some aspects of the final product characteristic and quality [33,36].…”

The Use of near Infrared Spectroscopy on Milk and Milk Products

“…Accuracy for the fat prediction was similar to previous studies on higher fat products of a similar nature. Kefir, a fermented dairy product, has also been assessed by NIR for pH and titratable acidity and lactic and acetic acids using diffuse reflectance across 1000-2500 nm 18,19 Predictive models suitable for screening purposes were developed, as is common with many studies on "real" samples obtaining a wide range of composition upon which to establish a correlation was challenging. The predictive model for lactic acid gave an RPD of 2.6 with an SEP of 0.16 g 100 mL -1 .…”

Implementação de um método robusto para o controle fiscal de umidade em queijo minas artesanal. Abordagem metrológica multivariada

“…9 Uma estratégia que vem sendo aplicada com sucesso para superar esses problemas é a utilização conjunta de espectroscopia no infravermelho próximo (NIRS, do inglês near infrared spectroscopy) e calibração multivariada, possibilitando o desenvolvimento de métodos rápidos, de baixo custo, que não usam reagentes ou solventes, praticamente não necessitam de pré-processamento das amostras e não geram resíduos. Nos últimos anos, esta estratégia foi utilizada com sucesso na determinação de diversos parâmetros, como gordura, umidade e proteína, em alguns tipos de queijos e outros derivados de leite, como queijo Danbo, 10 Cheddar, 11 Emmental, 12 Prato, 13 Kefir, 14 queijo fresco 15 e processado. 16 Entretanto, a grande maioria desses trabalhos analisou amostras de um número reduzido de produtores/origens/processos de fabricação, ou mesmo produziu as próprias amostras analisadas, o que não permitiu a incorporação de variância suficiente para o desenvolvimento de modelos adequados ao controle fiscal.…”