Bogdan Demczuk Junior

Leaves (LV), stems (STs), and inflorescences (IFs) of Pfaffia glomerata are usually discarded despite containing various bioactive compounds, especially β-ecdysone saponin. The objective was to optimize by desirability (DI) the ultrasound-assisted extraction (UAE) of bioactive compounds (total phenolics (TPCs), antioxidant activity (AA), and total saponins) from the aerial parts (LV, ST, and IF) of P. glomerata. Ideal drying conditions were determined and the drying kinetics were evaluated. LV, STs, and IFs were dried and extracted (0.06 g/mL 80% EtOH) in a USS (6 cm × 12 mm, pulse 3/6 s) by Central Composite Design (CCD), varying sonication power (140–560 W) and time (11–139 min), with TPC, AA by DPPH, and total saponin content as responses. The DI indicated that the higher TPC, AA, and saponin levels were obtained at 136.5 min and 137.87 W (STs), and 138.6 min and 562.32 W (LV and IFs). IF extracts contained higher saponin, TPCs, and AA. Higher β-ecdysone levels (3.90 mg g⁻¹) were present in the leaves. Several phenolics were detected in area parts of P. glomerata, the most abundant being p-coumaric acid (LV) and nicotinic acid (STs and IFs). These compounds provide potential health benefits. Phytol was found in all extracts. Extracts by UAE from leaves have antibacterial potential, with demonstrated inhibitory effects against S. aureus, E. coli, L. monocytogenes, S. Typhi, and P. aeruginosa, and presented bactericidal effects against E. coli, L. monocytogenes, and S. Typhi. Aerial parts of P. glomerata can be used to obtain extracts by UAE rich in bioactive compounds, providing complete utilization of the plant and sustainability to cultivation. This work represents the first report on the application of ecofriendly UAE techniques to extract bioactive compounds from the aerial parts of Brazilian ginseng.

Pickering emulsions, which are emulsions stabilized by colloidal particles, are being increasingly positioned as novel strategies to develop innovative food product solutions. In this context, the present work aims to develop Pickering emulsions stabilized by natural-based curcumin-loaded particles produced by the solid dispersion technique as promising mayonnaise-like food sauce alternatives. Two particle formulations (KC1 and KC2) were produced using k-carrageenan as the matrix material and different curcumin contents, then employed in the preparation of three Pickering emulsion formulations comprising different oil fractions (φ) and particle concentrations (KC1 φ 0.4 (4.7%), KC2 φ 0.4 (4.7%) and KC2 φ 0.6 (4.0%)). The creaming index tests accompanied by the optical microscopy analysis evidenced the good stability of the developed products for the tested period of 28 days. The final products were tested concerning color attributes, pH, oxidative stability, textural, and nutritional composition, and compared with two commercial mayonnaises (traditional and light products). Overall, the produced emulsions were characterized by a bright yellow color (an appealing attribute for consumers), an acidic pH (similar to mayonnaise), and a considerably improved oxidative stability, implying a foreseeable longer shelf life. The sauce KC1 φ 0.4 (4.7%) showed a similar texture to the light commercial mayonnaise, being a promising alternative to conventional sauces, holding a low-fat content and potentially added benefits due to the curcumin and virgin olive oil intrinsic properties.

A desidratação osmótica vem sendo utilizada como técnica de pré-tratamento para secagem por convecção com a intenção de fornecer ao consumidor um produto mais atrativo e com menores perdas causadas pelo calor. Alguns parâmetros influenciam na transferência de massa que ocorre durante a desidratação osmótica atingindo diretamente outros parâmetros como a perda de água, ganho de sólidos e perda de peso, obtendo-se a partir destes um coeficiente de desempenho. Assim, o presente trabalho teve como objetivo avaliar a influência da geometria no processo de desidratação osmótica de abóbora. Foram comparados dois tratamentos, considerando o corte da abóbora em fatias e em cubos. A desidratação osmótica ocorreu em incubadora a 30ºC com agitação de 35 rpm, por 3 horas, utilizando uma solução de cloreto de sódio (20%) e relação amostra:solução de 1:10 (m/m). Durante o tempo de processo, as amostras eram retiradas e os parâmetros de perda de peso, ganho de sólidos, perda de água e coeficiente de desempenho foram obtidos gravimetricamente. Constatou-se que para a perda de água e de peso, as maiores perdas encontradas foram nas amostras de fatias com 59% e 53% respectivamente. Os cubos apresentaram menor ganho de sólidos (6%) e menor perda de água e peso. Com relação ao coeficiente de desempenho, as fatias alcançaram o desempenho máximo em um menor período de tempo de processo, apesar do maior coeficiente (14,39) ser verificado para abóboras em cubo.

Starch is an important compound in human food, as it is a great source of energy. However, native starch has limitations that make it difficult to use, so it can be modified to acquire stability, improve as rheological characteristics of the masses or texture of the gels, among others. The objective of this study was to evaluate the chemical composition of native (3 brands) or modified by oxidation (potassium permanganate, sodium hypochlorite or citric acid) cassava starch, as well as the texture profile and the physical and chemical properties of the gels obtained therefrom. Because of the lower amylose content and the intermediate texture parameters of the gels, a commercial native starch brand was considered more suitable for chemical modification. The starch modification by oxidation with citric acid or sodium hypochlorite resulted in gels with less firmness, gumminess and adhesiveness and higher clarity, cohesiveness, resilience and elasticity than native starches. In addition, the nutritional value of the starch was not altered by chemical modification. The utilization of potassium permanganate modified starch resulted in gels with physical, chemical and appropriate texture, but it had excessively dark coloration, which limits its use in processed foods. It is recommended the use of modified starches by oxidation in food toppings, salad dressings, mayonnaise, as binding agents in confectionery products or as emulsifiers.

CARACTERIZAÇÃO E ESTABILIDADE DE PURÊ MISTO DE FRUTAS, FONTE DE FIBRA ALIMENTAR

DEGRADAÇÃO DA COR E DO ÁCIDO ASCÓRBICO NA DESIDRATAÇÃO OSMÓTICA DE KIWI*

In this work, it was used starch obtained from green banana (Musa cavendishii) and commercial corn (Zea mays) starch in order to compare the granule morphology and the rheological behavior of these gel-starches. Images of starch granules morphology were obtained from scanning electron microscope (SEM). The banana starch granules presented an oval and ellipsoidal shape with irregular diameters. Neverthless, the granules of corn starch showed a poliedric shape, with different sizes. The rheological behavior of gel starch solutions showed a non-newtonian character with a pseudoplastic behavior. Herschel-Bulkley model gave a good description on the rheological behavior of the gel starch. Banana gel-starch solutions showed higher values of shear stress and apparent viscosity when compared with corn gel-starch solutions. A progressive decrease in shear stress and viscosity occurred with the addition of sodium chloride and sucrose.