Using colorimetric spot test and digital imaging-based technique for volatile acidity determination in cachaça with the aid of a smartphone

• Published in: Microchemical journal Vol. 187; p. 108416
• Main Authors: de Oliveira Krambeck Franco, Mathews, Suarez, Willian Toito, Pereira, Gustavo Rodrigues Penha, Vilanculo, Castelo Bandane, Vieira, Maria Carolina Robaina, dos Santos, Vagner Bezerra, de Almeida, João Paulo Barbosa
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2023
• Subjects: Cachaça; Digital image; Quality control; RGB; Smartphone; Volatile acidity; Cachaça; Digital image; RGB; Smartphone; Volatile acidity; Quality control
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2023.108416

[Display omitted] •A low-cost digital image method was proposed to determine volatile acidity in cachaça.•A smartphone was used as a detector.•It is a tool for quality control, especially for the producers with limited resources.•The method can be easily disseminated in the manufacture environment. The present study reports the development and application of a novel method for the colorimetric determination of volatile acidity in cachaça using digital image. Cachaça is the most widely consumed beverage in Brazil and the development of efficient techniques for the determination of volatile acidity in this beverage is essentially important because this parameter directly reflects on the flavor and aroma of the drink. The method employed was digital image-based (DIB); this method involves the use of methyl orange as an indicator and the analysis of images captured and processed by a smartphone with a free application. A simple pretreatment of the samples employing a steam-dragging distillation for the extraction of volatile acids was performed before DIB analysis. The calibration curve related to anhydrous alcohol was found to be linear in the range of 25 to 275 mg/100 mL with an adjusted-R2 = 0.9912 and limit of detection of 6.70 mg/100 mL based on acetic acid content. The recovery assays conducted yielded recoveries ranging from 89.5 and 112 %. The technique proposed in this study is an easy, inexpensive and rapid tool for the quality control of cachaça, especially for small producers of the beverage who have limited financial resources. Moreover, this method is applicable to in situ analysis allowing to measure this parameter along the cachaça are produced being useful to monitor the volatile acidity.