Bioactive compounds and antioxidant activities of Brazilian hop (Humulus lupulus L.) extracts

Bioactive compounds from Brazilian hop (Humulus lupulus L.) cultivars were extracted by ultrasound and their phenolic profile compared with commercial hop from the USA. The most effective extraction conditions (solution of ethanol 49%, at 52 °C and a solid/liquid ratio of 1 g per 34 mL) for the total phenolic compounds (TPC) were determined using a Central Composite Rotatable Design. The Brazilian hop showed higher content of TPC (33.93 ± 0.67 mg GAE g⁻¹), total flavonoids (54.47 ± 0.10 mg QE g⁻¹) and higher antioxidant activity (ABTS: EC₅₀ 21.29 ± 1.36 μL mL⁻¹; DPPH: EC₅₀ 3.91 ± 0.17 μL mL⁻¹) when compared with the USA hop. The main phenolic compounds present in the extracts were the flavonoids isoquercitrin and quercetin. The antioxidant properties of the Brazilian hop extract had not been reported yet in the literature for this raw material, thus showing potential to be incorporated in polymeric films used as active packaging.     

Flour from 'fruits and vegetables' waste with addition of a South-American pepper (Capsicum baccatum) proposed as food ingredient

The objective of this work was to evaluate the physicochemical properties of previously characterised flours obtained by milling the solid waste from the manufacture of an isotonic drink produced with various fruits and vegetables (FVR) to which powdered pepper fruits (PF) were added. Aqueous extracts were also prepared and encapsulated for protecting their functional compounds and improving their solubility. The encapsulation yields of the spray-drying processes were 90% and 64% for PF and FVR-PF, respectively. The addition of PF to FVR improved antioxidant capacity, stability and appearance, providing reddish colour. FT-IR spectra reflected the addition of PF by changes in the absorbances at wave numbers typical of carotenoids, acylglycerols, chlorophylls and those related to antioxidant capacity. The encapsulated extracts could be applied when solubility is needed in hydrophilic media. The obtained flours with PF addition are suitably cheap, stable functional food ingredients for industrial uses, such as breading or seasoning ingredients.     

NIR spectroscopy and chemometric tools to identify high content of deoxynivalenol in barley

ABSTRACT

Deoxynivalenol (DON) is one of the mycotoxins produced mainly by the Fusarium graminearum species complex in small grain cereals, including barley. This toxin can cause alimentary disorders, immune function depression and gastroenteritis. The negative health effects associated with DON coupled to the increasing concern about green and rapid methods of analysis motivated this study. In this context, near infrared (NIR) spectroscopy data were applied for exploratory analysis to distinguish barley with high and low levels of DON contamination (> or <1250 µg/kg according to the European Union threshold), by Partial Least Squares-Discriminant Analysis (PLS-DA), and to verify the performance of Partial Least Squares-Regression (PLS-R) to predict DON concentration in barley samples. Maximum values of specificity and sensitivity were achieved in the calibration set; 90.9% and 81.9% were observed in the cross-validation set for the PLS-DA classification model. PLS-R quantification of DON in barley presented low values of error (RMSEC = 101.94 µg/kg and RMSEP = 160.76 µg/kg). Thus, we found that NIR in combination with adequate chemometric tools could be applied as a green technique to monitor DON contamination in barley.     

Multicriteria Decision Support for Selection of Alternatives Directed to Integrated Urban Water Management

Water Resources Management - The management of water resources in medium and large cities has been changing in recent years, mainly as a result of climate change and the sharp increase of...