Effect of the concentrations of maltogenic α-amylase and fat on the technological and sensory quality of cakes

The characteristics that define cake quality can be improved by the use of adequate ingredients and a correct balance of the formulation. Fat is used for its effect on softness and because it imparts flavor and calories. Enzymes such as maltogenic α-amylase can also have a positive effect on cake texture during storage by decreasing amylopectin re-crystallization and thus delaying starch retrogradation providing longer-lasting crumb softness. The objective of this study was to determine the effect of different concentrations of maltogenic α-amylase and fat on the technological and sensory characteristics of cakes. Therefore, balanced formulations with three different fat concentrations (20, 40, and 60 g/100 g, based on the flour content) were used to evaluate the addition of maltogenic α-amylase (0, 500, and 1000 mg/kg). Technological quality determinations were carried out on days 1, 7, 14, and 21 of storage. The best results in terms of cake quality (greater specific volume, higher crumb moisture content, lower crumb firmness, and greater sensory acceptance) were obtained with the combination of 20 g/100 g fat and 1000 mg/kg maltogenic α-amylase (based on the flour content), which proved to be an alternative to reduce the fat levels in the elaboration of this type of product.

Production of Crude Xylanase from Thermoascus Aurantiacus CBMAI 756 Aiming the Baking Process

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of a thermoascus aurantiacus thermostable enzyme cocktail on wheat bread quality

Thermophilic fungus Thermoascus aurantiacus (CBMAI 756) on solid-state fermentation using corncob as a nutrient source produces an enzyme pool with the potential to be used in bread making. In this paper, the use of this enzyme cocktail as a wheat bread improver was reported. Both products released by flour arabinoxylan degradation and bread quality were investigated. The main product released through enzyme activity after prolonged incubation was xylose indicating the presence of xylanase; however, a small amount of xylobiose and arabinose also confirmed the presence of xylosidase and α-L- arabinofuranosidase, respectively. Enzyme mixture in vitro mainly attacked water-unextractable arabinoxylan contributing to beneficial effect in bread making. The use of an optimal enzyme concentration (35 U xylanase/100 g of flour) increased specific volume (22%), reduced crumb firmness (25%), and reduced amylopectin retrogradation (17%) during bread storage. In conclusion, the enzyme cocktail produced by T. aurantiacus CBMAI 756 can improve wheat bread quality. © 2013 Elsevier Ltd.

Fibras alimentares: efeito na farinha, reologia das massas, qualidade e taxa de envelhecimento de pães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Utilização de farinha de quinoa no desenvolvimento de pães sem glúten

Pós-graduação em Engenharia e Ciência de Alimentos - IBILCE

Effect of inulin as prebiotic and synbiotic interactions between probiotics to improve fermented milk firmness

Inulin behaved as a prebiotic to improve firmness of skim milk fermented by (a) pure cultures of Lactobacillus acidophilus (La), Lactobacillus rhamnosus (Lr), Lactobacillus bulgaricus (Lb) and Bifidobacterium lactis (Bl), (b) binary co-cultures of them with Streptococcus thermophilus (St), or (c) a cocktail containing all them. Inulin addition to co-cultures and cocktail enhanced products firmness, either after 1 day (D1) or 7 days (D7) of cold storage, likely due to the increase in microbial growth induced by metabolic interactions among lactic acid bacteria and partial inulin metabolization. Co-culture firmness did in fact range from 0.33 N without inulin (St-Lb) after D1 and 0.55 N with inulin (St-Lr) after D7. Also cocktail cultures exhibited high values of firmness, ranging, as an average, from 0.43 N (D1) to 0.46 N (D7), which suggests that they could have been potentiated by the reciprocal synergistic effects of microorganisms in complex mixture. (C) 2011 Elsevier Ltd. All rights reserved.

Physicochemical and sensory characteristics of pan bread samples available in the Brazilian market

Pan bread samples available in the Brazilian market were evaluated for their physicochemical and sensory characteristics. Twelve pan breads, seven white and five whole grain breads, were evaluated. Moisture, water activity (Aw), firmness, and color (L*, a*, b*) of the crumb were evaluated on the first, fourth, seventh, and tenth days after purchasing the breads. Specific volume was evaluated on the first day of analysis with averages of 4.72 and 4.70 mL/g for the white and whole grain breads, respectively. The average results on the first day of analysis were: 37.03% and 41.23% moisture, 0.954 and 0.966 Aw, 276.27 and 267.83 gf firmness, 74.73 and 64.45 L* values, 0.37 and 3.85 a* values, and 15.51 and 18.98 b* values for the white and whole grain breads, respectively. The samples showed an increase in firmness, reduction in moisture and Aw, and no color changes over time. A survey conducted prior to the acceptance test showed that the three most important factors influencing purchase were taste (19.6%), tenderness (16.8%), and expiration date of the product (14.3%). The results showed that 37.2% of the panelists preferred white bread, 62.8% preferred bread with fibers, and 82.6% would probably or definitely buy white bread with fibers.

Influence of the wheat flour extraction degree in the quality of bread made with high proportions of β-glucan

β-glucan is currently one of the most important bioactive substances. Hence, there is a growing interest in the production of various foods containing β-glucan. The study examines the influence of the degree of wheat flour extraction in the quality of breads with high β-glucan content. Rheological tests were conducted on dough. Volume, mass, color and texture of bread were measured after baking. We observed that increasing the degree of extraction caused an increase in the storage and loss modulus. All of the bread made from the different flours were smaller in volume after the addition of β-glucan, although the yield increased. The crumb color of β-glucan-added breads was darker than the control samples. Control samples were higher in textural parameters (firmness, gumminess and chewiness). β-glucan-added samples had decreased porosity. The results revealed that using very strong flour with a high protein content results in a high quality β-glucan bread with a higher nutritional value due to the high total dietary fiber and β-glucan content.

Effect of milk fat concentration and gel firmness on syneresis during curd stirring in cheese-making

An experiment was undertaken to investigate the effect of milk fat level (0%, 2.5% and 5.0% w/w) and gel firmness level at cutting (5, 35 and 65 Pa) on indices of syneresis, while curd was undergoing stirring. The curd moisture content, yield of whey, fat in whey and casein fines in whey were measured at fixed intervals between 5 and 75 min after cutting the gel. The casein level in milk and clotting conditions was kept constant in all trials. The trials were carried out using recombined whole milk in an 11 L cheese vat. The fat level in milk had a large negative effect on the yield of whey. A clear effect of gel firmness on casein fines was observed. The best overall prediction, in terms of coefficient of determination, was for curd moisture content using milk fat concentration, time after gel cutting and set-to-cut time (R2 = 0.95).

Development of colour and firmness in strawberry crops is UV light sensitive, but colour is not a good predictor of several quality parameters

BACKGROUND: Strawberry (Fragaria × ananassa Duchesne var. Elsanta) plants were grown in polytunnels covered with three polythene films that transmitted varying levels of ultraviolet (UV) light. Fruit were harvested under near-commercial conditions and quality and yield were measured. During ripening, changes in the colour parameters of individual fruit were monitored, and the accuracy of using surface colour to predict other quality parameters was determined by analysing the correlation between colour and quality parameters within UV treatments. RESULTS: Higher exposure to UV during growth resulted in the fruit becoming darker at harvest and developing surface colour more quickly; fruit were also firmer at harvest, but shelf life was not consistently affected by the UV regime. Surface colour measurements were poorly correlated to firmness, shelf life or total phenolics, anthocyanins and ellagic acid contents. CONCLUSION: Although surface colour of strawberry fruits was affected by the UV regime during growth, and this parameter is an important factor in consumer perception, we concluded that the surface colour at the time of harvest was, contrary to consumer expectations, a poor indicator of firmness, potential shelf life or anthocyanin content. Copyright © 2011 Society of Chemical Industry

Influence of two methods of CaCl2 application and concentrations used to maintain passion fruit firmness

This is a report on the influence of the methods of postharvest application of CaCl2 in several concentrations, on the maintenance of the firmness of the sweet passion fruit (Passiflora alata Dryander). The fruits, picked in the pre-climateric stage, were selected desinfection with thiabendazol and submitted to CaCl2 in concentrations of 0% (control), 1%, 2%, 3% or 4% with two methods: immersion (for 2 h) and infiltration under vacuum and pressure (- 25 vacuum kPa, for 1 minute and, + 25 pressure kPa, for 1 min). All fruits were stored under refrigeration (9 degreesC, 85-90% RH), for 30 d. The fruits were evaluated for texture every 3 d. From the results, it is concluded that application of CaCl2 by infiltration favored the maintenance of fruit consistency during the first 18 days of storage. Fruits treated with 1% and 2% of CaCl2 were firmer than the others.

Aplicação de xilanase e/ou ciclodextria glicotransferase (CGTase) na produção de pães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da adição de CGTase e β-ciclodextrina na qualidade e taxa de envelhecimento de pães

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Decreased factor XIII availability for thrombin and early loss of clot firmness in patients with unexplained intraoperative bleeding

To explore relevant changes in unexplained intraoperative bleeding, we evaluated elements of the final steps of the coagulation cascade in 226 consecutive patients undergoing elective surgery. Patients were stratified for the occurrence of unexplained intraoperative bleeding according to predefined criteria. Twenty patients (8.8%) developed unexplained bleeding. The median intraoperative blood loss was 1350 mL (bleeders) and 400 mL (nonbleeders) (P < 0.001). Fibrinogen and Factor XIII (F. XIII) were more rapidly consumed in bleeders (P < 0.001). Soluble fibrin formation (fibrin monomer) was increased in bleeders throughout surgery (P < or = 0.014). However, F. XIII availability per unit thrombin generated was significantly decreased in bleeders before, during, and after surgery (P < or = 0.051). Computerized thrombelastography showed a parallel, significant reduction in clot firmness. We suggest that mild preexisting coagulopathy is not rare in surgical patients and probably can result in clinically relevant intraoperative bleeding. This hemostatic disorder shows impaired clot firmness, probably secondary to decreased cross-linking (due to a loss of F. XIII, both in absolute measures and per unit thrombin generated). We suggest that the application of F. XIII might be worthwhile to test in a prospective clinical trial to increase clot firmness in patients at risk for this intraoperative coagulopathy.