Determination of pH and acidity in green coffee using near‐infrared spectroscopy and multivariate regression

Araújo, Cintia da Silva; Macedo, Leandro Levate; Vimercati, Wallaf Costa; Ferreira, Adésio; Prezotti, Luiz Carlos; Saraiva, Sérgio Henriques

doi:10.1002/jsfa.10270

Cited by 23 publications

(10 citation statements)

References 35 publications

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“…The pH determination of the samples was carried out using a digital pH meter (Tecnal, TEC‐5, Piracicaba, Brazil). Acidity was determined by titration of sodium hydroxide, up to pH 8.20 (Araújo et al, 2020). The result was expressed in %, kg of citric acid per 100 kg of sample on a dry basis.…”

Section: Methodsmentioning

confidence: 99%

The impact of using vacuum and isomaltulose as an osmotic agent on mass exchange during osmotic dehydration and their effects on qualitative parameters of strawberries

Macedo

Corrêa

Vimercati

et al. 2022

J Food Process Engineering

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The impregnation of isomaltulose is an interesting strategy for the enrichment of strawberries since it is a carbohydrate with low glycemic and cariogenic indexes. The osmotic enrichment of strawberries with isomaltulose was performed considering the vacuum pulse in the first 0, 10, and 20 min in a total process time of 300 min, at 25°C. The tested solution concentrations were 25% and 35% (w w−1) of isomaltulose. The kinetics of solid gain, water loss, moisture content, and weight reduction were obtained. The fresh and final products had some physical and nutritional parameters evaluated. Osmotic processes resulted in a reduction of moisture content, water activity (aw), acidity, total anthocyanins and phenolic contents and antioxidant capacity, increased pH, influenced colorimetric parameters and caused shrinkage of the samples. The higher impregnation of isomaltulose was obtained with the vacuum pulse, which was 82% higher than the osmotic process without the vacuum pulse. The atmospheric process resulted in higher bioactive compounds levels and lower shrinkage and lower total color difference. Therefore, the 35% solution and use of vacuum were recommended when the objective was to maximize mass exchanges, while the 25% solution and without vacuum pulse were indicated for higher retention of strawberry bioactive compounds. The time of vacuum application at the beginning of the osmotic dehydration process and the use of osmotic solutions of different concentrations can result in different rates of dehydration and impregnation of isomaltulose in the strawberry and can influence important qualitative parameters. The evaluation of these factors helps in the optimization of the production of osmo‐dehydrated strawberries, increasing the process efficiency and the preservation of product quality. Practical Applications The time of vacuum application at the beginning of the osmotic dehydration process and the use of osmotic solutions of different concentrations can result in different rates of dehydration and impregnation of isomaltulose in the strawberry and can influence important qualitative parameters. The evaluation of these factors helps in the optimization of the production of osmo‐dehydrated strawberries, increasing the process efficiency and the preservation of product quality.

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Section: Methodsmentioning

confidence: 99%

The impact of using vacuum and isomaltulose as an osmotic agent on mass exchange during osmotic dehydration and their effects on qualitative parameters of strawberries

Macedo

Corrêa

Vimercati

et al. 2022

J Food Process Engineering

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“…The mixture was stirred on a magnetic stirrer for 20 min at 400 rpm. Three drops of phenolphthalein were added and titration was performed with 0.1 N sodium hydroxide, up to pH (Metrohm, 826 model) equal to 8.20 (phenolphthalein turning point), at room temperature (Araújo et al, 2020). The results were expressed as a percentage (g of malic acid per 100 g of sample).…”

Section: Methodsmentioning

confidence: 99%

Effect of drying air temperature on drying kinetics and physicochemical characteristics of dried banana

Macedo

Vimercati

Araújo

et al. 2020

J Food Process Engineering

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This study aimed to evaluate the influence of drying air temperature on drying kinetics and the physicochemical properties of dried bananas. Banana slices were dried at 40, 60, and 80°C. Drying was terminated when the samples had a moisture of 20%. Mathematical models were fitted to the moisture ratio. A generalized model of moisture was developed, to predict the moisture of samples as a function of drying time and temperature. The effective moisture diffusivity (Deff), activation energy and the drying rate (DR) were calculated. Electrical energy consumption was measured. The moisture, water activity, reducing and total sugar content, acidity, hardness, and color of the dried bananas were evaluated. The moisture decreased during drying, obtaining a mean value of 20.132%. All mathematical models fitted well to the MR data, with a determination coefficient greater than 0.95. The Midilli model was that which best fitted. The higher temperature resulted in higher Deff (3.538 × 10−9 m2 s−1) and DR, less drying time (120 min) and electrical energy consumption (4.319 kWh), higher reducing sugar content (47.51%) and hardness (28.187 N), lower acidity (1.038%), more yellow tonality (78.04°), and higher chromaticity (18.49) of the dried bananas. The optimum temperature for drying bananas was 80°C. Practical Applications Banana is a fruit widely consumed in the world. However, it is very perishable, causing great waste and financial loss. Convective drying is a simple and low‐cost method, widely used in fruit processing to produce new products and extend the shelf life of food. The dried banana is a product of good sensory acceptance and therefore drying is a good alternative for processing the banana pulp. The temperature of the drying air is one of the principal parameters of this process since it influences the drying kinetics and the physicochemical properties of the dry product. Therefore, it is important to study different drying air temperatures to determine the best drying condition for dried banana production, to optimize the dried banana process and properties.

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“…Kemudian nilai standard error baik untuk kalibrasi (root mean squared error of calibration atau RMSEC), validasi (root mean squared error of validation atau RMSEV), dan prediksi (root mean squared error of prediction atau RMSEP). Nilai RPD atau ratio prediction to deviation untuk kalibrasi (RPDkal) dan prediksi (RPDpred) dihitung menggunakan persamaan 5 dan 6 (Araújo et al 2020). Di mana SDval merupakan standar deviasi sampel validasi dan SDpred merupakan standar deviasi sampel prediksi.…”

Section: Metode Kemometrika Untuk Uji Keaslian Kopi Codot Lampungunclassified

Penggunaan UV-Vis Spektroskopi dan Kemometrika untuk Uji Keaslian Kopi Codot Lampung

Yulia

Ningtyas

Suhandy

2021

J. Ilmu. Pertan. Indones.

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Codot coffee from Tanggamus, Lampung is one of Indonesian specialty coffee with a very limited production. In this research, an authentication study for the Codot ground roasted coffee was conducted using UV-vis spectroscopy and chemometrics. A total of 330 samples of pure and adulterated Codot coffee was prepared. The adulterated Codot coffee samples were intentionally created by adding a regular coffee (non-Codot coffee) into pure Codot coffee samples with three levels of adulterations: low (10-20%), medium (30-40%), and high level (50-60%). All samples were 0,29 mm in particle size. The extraction procedure was performed with hot distilled water (98°C). The spectral data of coffee samples were acquired using a benchtop UV-visible spectrometer in the range of 190-1100 nm using a transmittance mode. The result showed that the pure and adulterated samples could be discriminated along PC1 and PC2 axis. The classification model was developed using LDA with 90,91% of accuracy could be obtained. The LDA model was used to classify the new samples and resulted in a sensitivity (SEN) of 100%, specificity (SPEC) of 76,67%, precision (PREC) of 78,13%, and accuracy (ACC) of 87,27% could be obtained. Using PLS regression, a PLS model was developed to quantify the percentages of Codot coffee adulteration and resulted in high of coefficient of determination both in calibration and validation (R2kal = 0,99 and R2val = 0,98). These results showed that UV-vis spectroscopy and chemometrics are suitable for authentication of Codot specialty coffee with RMSEP = 2,68% and RPD in prediction of 6,49. Keywords: authentication, LDA, PCA, PLS regression, UV-vis spectroscopy

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Determination of pH and acidity in green coffee using near‐infrared spectroscopy and multivariate regression

Cited by 23 publications

References 35 publications

The impact of using vacuum and isomaltulose as an osmotic agent on mass exchange during osmotic dehydration and their effects on qualitative parameters of strawberries

The impact of using vacuum and isomaltulose as an osmotic agent on mass exchange during osmotic dehydration and their effects on qualitative parameters of strawberries

Effect of drying air temperature on drying kinetics and physicochemical characteristics of dried banana

Penggunaan UV-Vis Spektroskopi dan Kemometrika untuk Uji Keaslian Kopi Codot Lampung

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