Mixture design applied to the study of bioethanol production from cheese whey and corn steep liquor

Abstract

Apart from creating many positive impacts, the growth of agribusiness has also generates concerns about the production of large amounts of undervalued by-products. Cheese whey and corn steep liquor (from corn flour production, a typical Brazilian food) are among these by-products that can be potential raw materials for obtaining new products such as bioethanol. The objective of this study was to apply an experimental design tool to examine different worts with cheese whey and corn steep liquor for the production of bioethanol. The worts containing 100 % corn steep liquor, and 25 % cheese whey with 75 % corn steep liquor supplemented with glucose were considered the best for the production of bioethanol, with fermentation efficiency reaching around 90 % for both of them. The use of pasteurization and antibiotics was effective in controlling lactic acid production, which results from bacterial contamination. The use of antibiotics showed advantages by reducing the maximum growth rate of yeast, which was reflected in higher rates of fermentation efficiency. The results obtained allowed reaching a high level of ethanol productivity.

Evaluation of traditional semi‐hard Brazilian cheeses using chemometric tools to identify possible denomination fraud

“…The mobile phase used was 6 mmol/L sulphuric acid prepared with ultrapure water (MilliQ, Millipore, São Paulo, Brazil), isocratic elution with a flow rate of 0.5 mL/min and an injection volume of 10 μL (Farias et al . 2016). Quantification was performed by comparing the retention time of lactic acid (Eqn 1) and lactose (Eqn 2) solutions.…”

“…The lactic acid and lactose contents were quantified by high-performance liquid chromatography (HPLC). The samples were macerated and diluted in distilled water (70°C) and subsequently shaken for 5 min (Farias et al 2016). The extracts were filtered using a qualitative filter and then through a 0.45 μm nylon filter (Waters, Milford, MA, USA).…”

“…The chromatographic system was an Alliance 2695 model (Waters) equipped with Bio-Rad HPX 87H column (300 × 7.8 mm), refractive index detector (RI 2414; Waters) and test temperature of 30°C. The mobile phase used was 6 mmol/L sulphuric acid prepared with ultrapure water (MilliQ, Millipore, São Paulo, Brazil), isocratic elution with a flow rate of 0.5 mL/min and an injection volume of 10 μL (Farias et al 2016). Quantification was performed by comparing the retention time of lactic acid (Eqn 1) and lactose (Eqn 2) solutions.…”

Combining chemical analysis, sensory profile, CATA, preference mapping and chemometrics to establish the consumer quality standard of Camembert‐type cheeses

“…The elution system was isocratic, with sulphur acid solution at 6 mmol/L with a 0.5 mL/min flow rate. The injection volume was 10 µL, and the separation of compounds was performed by comparison with calibration curves (Farias et al 2016). The texture profile was performed on the cheeses with 14, 21 and 28 days of ripening, to mimic the sensory perception.…”