Foam-Mat Freeze-Drying of Blueberry Juice by Using Trehalose-β-Lactoglobulin and Trehalose-Bovine Serum Albumin as Matrices

This study aimed to evaluate the effect of pure protein compounds and trehalose incorporated into blueberry juice for foam-mat freeze-drying on the foam and powder properties. Foam-mat freeze-drying (FMFD) of blueberry juice was tested at − 55 °C for 24 h. Matrices used were trehalose + β-lactoglobulin (T3BL1) and trehalose + bovine serum albumin (T3A1) and compared with maltodextrin + whey protein isolate (M3W1). Physicochemical properties of foam and powder, e.g., foam stability, foam density, moisture, rehydration time, color, particle morphology, total phenolic, and anthocyanins (total and individuals), were investigated. T3BL1 and T3A1 had more stable foam than M3W1. However, overrun of T3BL1 and T3A1 foamed were inferior to the M3W1 sample. The M3W1 sample recovered 79% powder (dry weight) and was superior to others. Rehydration time of powdered T3BL1 and T3A1, with bulk densities of 0.55–0.60 g cm−3, was the fastest (34–36 s). The blueberry powders of M3W1 showed more irregular particle size and shape, while the samples with trehalose and pure proteins generated particles of more uniform size with obvious pores. T3BL1 and T3A1 showed less redness (a*) values than the M3W1 product. All samples were considered pure red due to hue values < 90. M3W1 was superior in total phenolic content (TPC) and total monomeric anthocyanins (TMA) compared with both samples made with trehalose + β-lactoglobulin and trehalose+bovine serum albumin. Delphinidin-3-glucoside (Del3Gl) concentration was found to be higher in M3W1. Also, M3W1 had higher cyanidin-3-glucoside (Cyn3Gl) and malvidin-3-glucoside (Mal3Gl) concentration. M3W1 also prevented the degradation of these bioactive compounds better than the other FMFD samples. The use of pure proteins and trehalose as matrices in the FMFD process had little advantage compared with maltodextrin/whey protein isolate. Thus, maltodextrin/whey protein isolate seems an ideal matrix for the manufacture of FMFD blueberry

Influence Of Protein-pectin Electrostatic Interaction On The Foam Stability Mechanism.

This study aimed at evaluating the effect of three independent variables: biopolymer concentration (egg white proteins and pectin) (2.0-4.0%, w/w); protein:pectin ratio (15:1-55:1); and temperature (70-80 °C), at pH 3.0, using a central composite design on the foaming properties (overrun, drainage and bubble growth rate). Foams produced with protein:pectin ratio 15:1 showed the lowest bubble growth rate and the greatest drainage, whereas protein:pectin ratio 55:1 presented the lowest drainage. Complexes obtained with protein:pectin ratio 15:1 were close to electroneutrality and showed larger size (95.91 ± 8.19 μm) than those obtained with protein:pectin ratio 55:1 (45.92 ± 3.47 μm) not electrically neutral. Larger particles seemed to build an interfacial viscoelastic network at the air-water interface with reduced gas permeability, leading to greater stability concerning the disproportionation. Soluble complexes of smaller sizes increased viscosity leading to a low drainage of liquid and inhibiting the bubbles coalescence.10355-6

Effect Of Ph And Interaction Between Egg White Protein And Hydroxypropymethylcellulose In Bulk Aqueous Medium On Foaming Properties

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Egg white protein (EW) is used as surface-active ingredient in aerated food and hydroxypropylmethylcellulose (HPMC) is a polysaccharide that behaves as a surfactant. This study aimed at investigating the effects of process parameters biopolymer concentration (2.0-5.0%, w/w), EW:HPMC ratio (2:1-18:1), pH (3.0-6.0), and the influence of biopolymers' behavior in aqueous solution at different pH on the foaming properties (overrun, drainage, and bubble growth rate). Process parameters had effect on foaming properties. The pH was the major factor influencing the type of EW/HPMC interaction and affected the foaming properties of biopolymer mixture. At pH 3.0, EW and HPMC showed thermodynamic compatibility leading to better foaming properties, higher foaming capacity, and stability than without HPMC addition whereas at pH 4.5 and 6.0,EW and HPMC are incompatible that causes lower stability concerning the disproportionation comparing to foam without HPMC. At pH between 3.0 and 4.5, HPMC improves foaming properties of aerated products. (C) 2015 Elsevier Ltd. All rights reserved.1252634Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)EMBRAPA (Brazilian Agricultural Research Corporation)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [FAPESP 2011/50067-9

Propriedades tecnológicas e sensoriais de pães fortificados com ferro

O objetivo deste trabalho foi comparar as características tecnológicas e sensoriais de pães tipo forma fortificados, com três diferentes fontes de ferro (ferro reduzido, pirofosfato de ferro e sulfato ferroso monohidratado microencapsulado) na concentração de 4,2mg de ferro/100g de farinha, em comparação com uma formulação padrão. A adição de sulfato ferroso microencapsulado influenciou as propriedades farinográficas (Índice de Tolerância à Mistura e estabilidade) e extensográficas (resistência à extensão e extensibilidade) da farinha de trigo. Quanto à cor e às propriedades sensoriais, todas as amostras de pães contendo compostos de ferro não diferiram da amostra padrão. A firmeza dos pães foi avaliada nos tempos de estocagem de 1, 3, 5, 9, 13 e 16 dias. As amos-tras contendo pirofosfato de ferro resultaram em pães mais macios, enquanto que os mais firmes foram os contendo ferro reduzido. Os compostos de ferro testados podem ser utilizados no preparo de pães com características sensoriais (aparência e sabor) equivalentes ao padrão. Desta forma, o critério de escolha dependerá de sua viabilidade econômica e disponibilidade comercial

Effect Of Ph And Interaction Between Egg White Protein And Hydroxypropymethylcellulose In Bulk Aqueous Medium On Foaming Properties.

Egg white protein (EW) is used as surface-active ingredient in aerated food and hydroxypropylmethylcellulose (HPMC) is a polysaccharide that behaves as a surfactant. This study aimed at investigating the effects of process parameters biopolymer concentration (2.0-5.0%, w/w), EW:HPMC ratio (2:1-18:1), pH (3.0-6.0), and the influence of biopolymers' behavior in aqueous solution at different pH on the foaming properties (overrun, drainage, and bubble growth rate). Process parameters had effect on foaming properties. The pH was the major factor influencing the type of EW/HPMC interaction and affected the foaming properties of biopolymer mixture. At pH 3.0, EW and HPMC showed thermodynamic compatibility leading to better foaming properties, higher foaming capacity, and stability than without HPMC addition whereas at pH 4.5 and 6.0, EW and HPMC are incompatible that causes lower stability concerning the disproportionation comparing to foam without HPMC. At pH between 3.0 and 4.5, HPMC improves foaming properties of aerated products.12526-3