Bioactive compounds and antioxidant capacity in freeze-dried red cabbage by FT-NIR and MIR spectroscopy and chemometric tools

Red cabbage is a widely consumed vegetable worldwide due to its popularity and affordability. This vegetable has a significant content of bioactive compounds known for their antioxidant properties. Several traditional methodologies are commonly used to measure the total phenolic and anthocyanin content (TPC and TAC) and the antioxidant capacity. However, these methods generate toxic waste, pose a threat to the operator, and are time-consuming. This study determined the potential use of near and mid-infrared (NIR and MIR) spectroscopy, along with chemometric tools to evaluate TPC, TAC, and antioxidant capacity in red cabbage. The PLS models obtained by MIR to predict TAC (RMSEP = 0.35 mg/g), TPC (RMSEP = 0.34 mg GAEq/g), oxygen radical absorbance capacity (ORAC) (RMSEP = 125.31 μMol Eq trolox/g), and trolox equivalent antioxidant capacity (TEAC) (RMSEP = 0.33 μMol Eq trolox/g), and 2,2-diphenyl-picrylhydrazyl (DPPH) (RMSEP = 11.11 μMol Eq trolox/100 g) displayed good parameters of errors of prediction. Models constructed with NIR to predict TAC (RMSEP = 0.47 mg/g), TPC (RMSEP = 0.41 mg GAEq/g), ORAC (RMSEP = 116.34 μMol Eq trolox/g), TEAC (RMSEP = 0.29 μMol Eq trolox/g), and DPPH (RMSEP = 11.47 μMol Eq trolox/100 g) had similar results. These results suggest that the vibrational spectroscopic techniques of NIR and MIR associated with chemometrics could be successfully used for determination of TAC, TPC, and antioxidant capacity. They are sustainable and efficient methods that reduce toxic waste and time when compared to current protocols137885COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESSem informaçã

Quality evaluation of frozen guava and yellow passion fruit pulps by NIR spectroscopy and chemometrics

The present study investigated the application of near infrared spectroscopy as a green, quick, and efficient alternative to analytical methods currently used to evaluate the quality (moisture, total sugars, acidity, soluble solids, pH and ascorbic acid) of frozen guava and passion fruit pulps. Fifty samples were analyzed by near infrared spectroscopy (NIR) and reference methods. Partial least square regression (PLSR) was used to develop calibration models to relate the NIR spectra and the reference values. Reference methods indicated adulteration by water addition in 58% of guava pulp samples and 44% of yellow passion fruit pulp samples. The PLS models produced lower values of root mean squares error of calibration (RMSEC), root mean squares error of prediction (RMSEP), and coefficient of determination above 0.7. Moisture and total sugars presented the best calibration models (RMSEP of 0.240 and 0.269, respectively, for guava pulp; RMSEP of 0.401 and 0.413, respectively, for passion fruit pulp) which enables the application of these models to determine adulteration in guava and yellow passion fruit pulp by water or sugar addition. The models constructed for calibration of quality parameters of frozen fruit pulps in this study indicate that NIR spectroscopy coupled with the multivariate calibration technique could be applied to determine the quality of guava and yellow passion fruit pulp85209214FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2015/15848-

Detection of fruit pulp adulteration using multivariate analysis: comparison of NIR, MIR and data fusion performance

This study aimed at developing control charts and classification models to investigate sugar and water addition in guava pulp applying near- and mid-infrared (NIR and MIR) spectroscopies and low-level data fusion to compare performance of them. The pulp was produced in a pilot plant (authentic samples) during the harvest season in São Paulo (Brazil), and part of samples was adulterated with sugar or water. Authentic and adulterated samples were analyzed by NIR and MIR. The spectra data obtained were preprocessed, and the principal component analysis was applied. MIR spectra data presents a fingerprint region, which is an important tool to differ authentic and adulterated samples. Control charts and classification models (SIMCA, k-NN, and PLS-DA), which were authenticated by external validation, were used to discriminate authentic from adulterated samples (sugar or water in different concentrations). It was possible to differentiate adulterated from authentic samples through control charts, except for water-adulterated samples using NIR spectral. The models presented excellent values of sensitivity, specificity, accuracy, and efficiency. However, k-NN presented better performance. The results obtained by data fusion presented worse performance than the models based in only one of the techniques. Therefore, these results suggested that NIR and MIR techniques can be used for adulteration detection; however, MIR control charts and k-NN models are more effective to detect sugar or water adulteration in guava pulp1313571365COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação2015/15848-

Rapid assessment of total phenolic and anthocyanin contents in grape juice using infrared spectroscopy and multivariate calibration

Grape juice is rich in bioactive compounds that are known for beneficial effects, such as prevention of cancer and diabetes. The determination of the content of these compounds has been carried out following several protocols which generated toxic waste. In this context, infrared spectroscopy in near (NIR) and mid- (MIR) regions were applied for the determination of total phenolic and anthocyanin content (TPC and TAC, respectively) in grape juice for being a rapid green methodology. Calibration models were built using partial least squares regression (PLSR) to predict TPC and TAC in grape juice. MIR and NIR had a similar satisfactory performance to predict TAC presenting low RMSEP (4.22 mg/100 mL and 4.44 mg/100 mL). In TPC prediction, MIR presented a RMSEP (0.21 mg GAE/mL) slightly better in comparison to the one presented by NIR (0.37 mg GAE/mL). Errors can be considered acceptable for the determination of TPC and TAC in grape juice, qualifying both infrared techniques to replace traditional wet methodologies, with the advantage of being environmentally friendly1016091615CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação2015/15848-

Quality control of cashew apple and guava nectar by near infrared spectroscopy

Near infrared (NIR) spectroscopy along with multivariate calibration was used for quality control of cashew apple and guava nectars. Total acidity, total sugars, soluble solids, pH, and ascorbic acid contents were analyzed by traditional wet chemical methodologies and NIR. The spectral data were preprocessed with multiplicative scatter correction, mean center and first derivative (Savitsky-Golay). The models presented adequate standard errors of calibration (root mean square error of calibration – RMSEC) and prediction (root mean square error of prediction – RMSEP), respectively, to cashew apple nectar (acidity = 0.022% and 0.025%, total sugars = 0.58% and 0.60%, pH = 0.068 and 0.123, ascorbic acid = 4.61 mg/100 g and 4.80 mg/100 g), and to guava nectar (acidity = 0.019% and 0.024%, total sugars = 0.297% and 0.315%, soluble solids = 0.242 and 0.301 °Brix, pH = 0.063 and 0.107, ascorbic acid = 6.41 mg/100 g and 7.44 mg/100 g). Results showed that replacement of traditional methodology by NIR can be viable and recommended since it is a fast, green, easy-to-handle, safe technique, able to process many samples, and parameters in a short time564146CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informação2015/15848-

Survey of Freshly Harvested Oat Grains from Southern Brazil Reveals High Incidence of Type B Trichothecenes and Associated Fusarium Species

The current study investigated the fungal diversity in freshly harvested oat samples from the two largest production regions in Brazil, Paraná (PR) and Rio Grande do Sul (RS), focusing primarily on the Fusarium genus and the presence of type B trichothecenes. The majority of the isolates belonged to the Fusarium sambucinum species complex, and were identified as F. graminearum sensu stricto (s.s.), F. meridionale, and F. poae. In the RS region, F. poae was the most frequent fungus, while F. graminearum s.s. was the most frequent in the PR region. The F. graminearum s.s. isolates were 15-ADON genotype, while F. meridionale and F. poae were NIV genotype. Mycotoxin analysis revealed that 92% and 100% of the samples from PR and RS were contaminated with type B trichothecenes, respectively. Oat grains from PR were predominantly contaminated with DON, whereas NIV was predominant in oats from RS. Twenty-four percent of the samples were contaminated with DON at levels higher than Brazilian regulations. Co-contamination of DON, its derivatives, and NIV was observed in 84% and 57.7% of the samples from PR and RS, respectively. The results provide new information on Fusarium contamination in Brazilian oats, highlighting the importance of further studies on mycotoxins