Identification of the profile of volatile compounds in commercial kombucha added with hibiscus (Hibiscus rosa-sinensis) / Identificação do perfil de compostos voláteis em kombucha comercial adicionado de hibisco (Hibiscus rosa-sinensis)

Kombucha is a fermented drink from a symbiotic culture of bacteria and yeasts (SCOBY) and has been consumed due to its sensory and antioxidant characteristics that provide several health benefits, in addition to scientific evidence showing that there are variations in the chemistry of these kombucha. Therefore, this study aimed to investigate the profile of volatile compounds from kombucha commercials using the GC-MS-SPME technique. Five kombucha samples from commercial points on Rio de Janeiro City were analyzed. The profile of volatile compounds was evaluated using the SPME technique using a PDMS/DVB/CAR triple fiber. Volatiles were identified by comparing their mass spectra with a NIST and IRL. The results indicated that the profile of volatile compounds analyzed was constituted by nine classes of compounds, namely, esters, ketones, carboxylic acids, alcohols, aldehydes, amines, hydrocarbons, lactones and terpenes. Among them, the esters were the majority, ranging from 20.0 to 28.0 %, it was also possible to observe that 2-Octenal was the most abundant compound in all samples, ranging from 52.7 to 63.0 %. Thus, it is seen that the profile of volatile compounds in kombucha is found by a complex mixture of compounds belonging to different classes and which have the esters as the most representative due to the fermentation process that occurs during the production of kombucha

Quimiometria na classificação de leite cru refrigerado

Objetivou-se avaliar as correlações entre os parâmetros de qualidade do leite cru refrigerado produzido em diferentes unidades produtoras através da análise de componentes principais (PCA). Foram consideradas as seguintes variáveis: acidez, crioscopia, densidade, teor de gordura, extrato seco total (EST), extrato seco desengordurado (ESD), pH, contagem de células somáticas (CCS), contagem de bactérias totais (CBT) e teste de redução do azul de metileno (TRAM). Foi observado que as amostras se agruparam em cinco diferentes grupos: (I) não teve influência de nenhum vetor, (II) correlacionados com os parâmetros de CCS e CBT, possivelmente por apresentarem maiores contagens, sinalizando que possuem padrão de qualidade inferior em comparação com as demais amostras, o grupo (III) sofreu maior influência dos parâmetros de ESD, acidez, densidade e TRAM, enquanto o grupo (IV) foi discriminado majoritariamente pelos vetores de EST e gordura, indicando que as amostras exibem maior teor desses parâmetros e são oriundas de leite de boa qualidade, o grupo (V) foi caracterizado por uma correlação negativa com os vetores de EST, gordura, crioscopia e pH, evidenciando que essas amostras possuem um padrão de qualidade inferior. A partir da análise de PCA, as amostras foram agrupadas de acordo com a similaridade, permitindo constatar que os vetores que mais contribuíram para a discriminação das diferentes amostras de leite foram os valores de CCS e CBT

Feasibility of utilising ricotta cheese whey in chocolate ice cream / Viabilidade de utilização do soro de queijo ricota em sorvete de chocolate

The purpose of this study was to evaluate the feasibility of the application of Ricotta Cheese Whey (RCW) in ice creams by assessing the impact of this addition on different quality factors. Five samples of chocolate ice cream were developed with a difference between the formulations only regarding the proportion of RCW (25, 50, 75, and 100% (w/w)) in the ice cream mix. The sample developed only with whole milk (WM) was also analysed. The ice creams were subjected to several proximate composition, physico-chemical properties, microbiological quality, and sensory analysis. The results showed that the increase in the level of RCW caused a decrease in the nutrient content and that their application in ice cream significantly reduced the fat content. A small change in the texture and instrumental colour of the ice cream, which indicated more hardness and greater colour intensity, did not negatively affect the sensory tests. In addition, the experimental ice creams showed greater resistance to melting (no desorption signals) when incorporating RCW in the ice cream. In the acceptance test, samples developed with RCW obtained averages 7.06 (out of max. 9.00) for general taste and most consumers said they would buy the products. The importance of consuming low-fat products and preserving the environment is not a recent concern, and the use of RCW in ice cream proved to be a suitable alternative with a positive contribution to the economy, industry, consumers, and the environment.