Utilisation of front face fluorescence spectroscopy as a tool for the prediction of some chemical parameters and the melting point of semi-hard and hard cheeses: a preliminary study

The objective of this preliminary study was to evaluate the usefulness of front face fluorescence spectroscopy to predict some chemical parameters [pH, fat, dry matter (DM), fat in DM, total nitrogen (TN) and water soluble nitrogen (WSN)] and cheese meltability of semi-hard and hard cheeses. Dynamic testing rheology was used to determine the melting point of cheeses corresponding to the temperature at which loss tangent (tan δ) = 1. Tryptophan and vitamin A fluorescence spectra were, also, recorded on cheese samples at 20 °C. The partial least squares (PLS) regression with the leave one-out cross-validation technique was used to build up calibration models. Excellent predictions were obtained from the tryptophan and vitamin A models for fat (R ² = 0.99 and 0.97, respectively), DM (R ² = 0.94 and 0.96, respectively), fat in DM (R ² = 0.92 and 0.99, respectively), TN (R ² = 0.91 and 0.91, respectively). Excellent predictions were also obtained for WSN (R ² = 0.96) and melting point (R ² = 0.97) from vitamin A spectra, while only good predictions for these two parameters (R ² = 0.90 and R ² = 0.87, respectively) were obtained from tryptophan spectra. The results for pH were good (R ² = 0.82) and approximate (R ² = 0.76) with tryptophan and vitamin A, respectively.     

Quality characteristics of low-fat chicken nuggets: effect of common salt replacement and added bottle gourd (Lagenaria siceraria L.)

BACKGROUND: There is growing demand for the meat products having healthier characteristics. In an endeavour to develop low‐salt, low‐fat and high‐fibre chicken nuggets an investigation was carried out to observe the effects of partial replacement (40%) of sodium chloride in pre‐standardised low‐fat chicken nuggets (Control, 20 g kg^?1 NaCl) with a salt substitute blend as well as incorporation of bottle gourd (Lagenaria siceraria L.) in the resulting low‐salt, low‐fat products at three different levels, i.e. 50, 75 and 100 g kg^?1 (Treatments, 12 g kg^?1 NaCl) on the various quality attributes. RESULTS: Sodium chloride replacement decreased (P < 0.01) emulsion and product pH, cooking yield, moisture, ash, yellowness, hue value and textural properties. pH values, moisture and dietary fibre increased (P < 0.01) while cooking yield, % protein, textural properties and total cholesterol were decreased with the incorporation of bottle gourd in low‐salt, low‐fat nuggets. Sensory attributes of the product were not affected with salt replacement; however, inclusion of bottle gourd at higher levels decreased (P < 0.05) flavour and texture scores. CONCLUSION: The results suggest that low‐salt, low‐fat and high‐fibre chicken nuggets can be developed with the use of a salt substitute blend and bottle gourd without affecting their acceptability. Copyright © 2012 Society of Chemical Industry     

Application of Weibull distribution model to describe the vacuum pulse osmotic dehydration of sardine sheets

Application of Weibull frequency distribution model was investigated for predicting the moisture and salt contents of sardine sheets during vacuum pulse osmotic dehydration using brine at different concentrations (0.15-0.27 g NaCl/g), temperatures (30-38 °C), and applying a vacuum pulse at 11.0 kPa for 10 min. The high regression coefficients (R²>0.99) and low mean relative error (<10%) indicated the acceptability of Weibull model for predicting both moisture and salt contents. The scale parameters for moisture and salt contents as a function of temperature all followed an Arrhenius relationship. Models for scale and shape parameters for moisture and salt contents as a function of brine concentration and temperature were found.     

Partial replacement of fat and salt in liver pâté by addition of Agaricus bisporus and Pleurotus ostreatus flour

The effect of incorporation of 7.5% (hydrated 50/50 w/w) and 10% (hydrated 70/30 w/w) of Agaricus bisporus (Ab) and Pleurotus ostreatus (Po) flours as partial replacers of fat and salts (sodium chloride and phosphates) on physicochemical properties, microbiological and sensory properties of pâté was studied during cold storage. Mushroom flours increased moisture, dietary fibre and protein contents improving the nutritional value of pâtés. Mushroom flour influenced the colour parameters, especially Ab, and gave harder pâtés in 10% mushroom flour addition. Sensorially, the odour and taste of 7.5% of mushroom flour were considered acceptable, and its addition hydrated in a ratio 50/50 w/w should be the most suitable to improve the nutritional value of this product without significantly affecting the sensory properties. The addition of Ab and Po flours was a feasible strategy to replace fat and salts in pâté.     

Effect of pulse flours on the physiochemical characteristics and sensory acceptance of baked crackers

Pulse flours offer nutritional alternatives to wheat flour in the production of baked snacks due to their high protein and fibre levels and low glycaemic index. In this study, broad‐bean (Vicia faba), yellow‐pea and green‐pea (Pisum sativum) flours were each blended with wheat flour at 40% in the formulation of chemically leavened crackers. The effects of flour type and baking time on the physiochemical properties, sensory acceptability, nutritional composition and antioxidant activity of the crackers were observed in comparison with 100% wheat crackers. Broad‐bean crackers had the highest protein content and antioxidant activity (13 g per 100 g DM and 38.8 mgAAE per 100 g DM, respectively). Yellow‐pea crackers had the highest fibre content (12 g per 100 g DM). Physical dimensions and colour attributes were significantly affected by pulse‐flour substitution. Yellow‐pea and broad‐bean crackers were significantly preferred by consumers compared to the control, demonstrating the potential application of these flours to improve the eating quality and nutritional profile of crackers.     

Nutrient and functional properties of composite flours processed from pregelatinised barley,sprouted faba bean and carrot flours

Mixture response surface methodology was used to study the effects of blending ratio (barley, faba bean and carrot) and faba bean sprout durations (1, 2 and 3 days) to improve nutrients and functional properties of bassoo (a traditional food in Ethiopia). Addition of sprouted and roasted faba bean and dried carrot flours significantly (P < 0.05) increased iron, zinc, total carotenoid (TC), water solubility index (WSI), water hydration capacity (WHC) and a_w. Models generated were fitting with high coefficient of determination R²: 0.74, 0.94, 0.99, 0.99, 0.94, 0.94, 0.94, 0.96 and 0.99 for iron, zinc, TC, condensed tannin, ferric reducing power, a_w, WAI, WSI and WHC, respectively. The study showed blending of pregelatinised barley, sprouted and roasted faba bean and dried carrots flours from 50% to 65%, 25% to 35% and 10% to 15%, respectively, led to achieve desired functional and nutritional quality studied.     

Particle Size Fractionation of High-Amylose Rice (Goami 2) Flour as an Oil Barrier in a Batter-Coated Fried System

The particle size effects of high-amylose rice (Goami 2) flour on quality attributes of frying batters were characterized in terms of physicochemical, rheological, and oil-resisting properties. High-amylose rice flours were fractionated into four fractions (70, 198, 256, and 415 μm) of which morphology was also analyzed by scanning electron microscopy. Rice flour with smaller particle size exhibited a higher degree of starch gelatinization, giving rise to increased pasting parameters. When the rice flours were incorporated into frying batters, higher steady shear viscosity was observed in the batters with finer rice flour, which could be well characterized by the power law model. In addition, the dynamic viscoelastic properties of the batters were enhanced by the use of rice flour with smaller particle size, which also caused an increase in batter pickup. When subjected to deep fat frying, the batters with finer rice flour exhibited reduced moisture loss. Furthermore, the oil uptake was found to have a positive correlation with the particle size of rice flour (R ²?=?0.88), even showing the reduction of oil uptake by 15%. It could be synergistically attributed to the formation of outer starch granular layers, high batter viscosity/pickup, and reduced moisture loss by finer rice flour.     

Single‐cell protein production through microbial conversion of lignocellulosic residue (wheat bran) for animal feed

Agricultural residue (wheat bran) rich in carbohydrates was utilized in the fermentation process to produce microbial biomass. Single‐cell biomass consists of the dried cells of microorganisms, which are used as protein supplements in human food and in animal feed. In the present study, two different microorganisms (Candida utilis and Rhizopus oligosporus) were studied for biomass production. To enhance the nutritional contents of wheat bran, a number of different fermentation parameters (effect of inoculum size, age of inoculum, incubation period, moisture to substrate ratio and incubation temperature) were optimized. Maximum yield was obtained at an inoculum size of 10% (v/w), with the age of the inoculum being a 48 h old culture. A fermentation period of 48 h was found to give the maximum protein yield and viable counts of yeast cells and mould hyphae. The microorganisms showed good growth at 30 °C. After complete optimization of the fermentation parameters, a batch of wheat bran was fermented with C. utilis and R. oligosporus under the optimized conditions, resulting in a maximum crude protein yield of 41.02% compared with the 4.21% crude protein of the non‐fermented wheat bran. Copyright © 2015 The Institute of Brewing & Distilling     

Evaluation of the TLC quantification method and occurrence of deoxynivalenol in wheat flour of southern Brazil

ABSTRACT

The study evaluated a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) extraction method for use with a TLC quantification procedure for deoxynivalenol (DON). It also surveyed DON occurrence in wheat flour from the southern region of Brazil. Forty-eight wheat flour samples were analysed, divided into 2 different harvest lots, each consisting of 24 different brands. The detection and quantification limits of the method were 30 and 100 ng of DON on the TLC plate. The various concentrations of DON presented high linearity (R² = 0.99). A negative matrix effect (?28%) of the wheat flour was verified, with suppression of the chromatographic signal of DON, and 80.2–105.4% recovery. The TLC method was reliable for DON evaluation, with a coefficient of variation of less than 10%. High-performance liquid chromatography of lot 2 samples confirmed the presence of DON in all samples identified DON-positive by the TLC technique. Of the 48 wheat flour samples in lots 1 and 2 analysed by TLC, 33.3 and 45.8% of the samples respectively were above the Brazilian legislation limit. Correlations were observed between the water activity and DON content, and between the fungal count and moisture content of the wheat flours.     

Evaluation of processed green and ripe mango peel and pulp flours (Mangifera indica var. Chokanan) in terms of chemical composition,antioxidant compounds and functional properties

BACKGROUND: Mango is a highly perishable seasonal fruit and large quantities are wasted during the peak season as a result of poor postharvest handling procedures. Processing surplus mango fruits into flour to be used as a functional ingredient appears to be a good preservation method to ensure its extended consumption. RESULTS: In the present study, the chemical composition, bioactive/antioxidant compounds and functional properties of green and ripe mango (Mangifera indica var. Chokanan) peel and pulp flours were evaluated. Compared to commercial wheat flour, mango flours were significantly low in moisture and protein, but were high in crude fiber, fat and ash content. Mango flour showed a balance between soluble and insoluble dietary fiber proportions, with total dietary fiber content ranging from 3.2 to 5.94 g kg^?1. Mango flours exhibited high values for bioactive/antioxidant compounds compared to wheat flour. The water absorption capacity and oil absorption capacity of mango flours ranged from 0.36 to 0.87 g kg^?1 and from 0.18 to 0.22 g kg^?1, respectively. CONCLUSION: Results of this study showed mango peel flour to be a rich source of dietary fiber with good antioxidant and functional properties, which could be a useful ingredient for new functional food formulations. Copyright © 2011 Society of Chemical Industry     

Physicochemical and functional properties of full‐fat and defatted Moringa oleifera kernel flour

Full‐fat and defatted Moringa oleifera kernel flours were analysed for their functional properties. The effect of pH and NaCl concentrations on the functional properties of the flours was investigated following standard procedures. The protein content of full‐fat and defatted flour was 36.18 and 62.76 g/100 g, respectively. The concentrations of other proximate constituents of the defatted flour were higher than those of the full‐fat flour. Nitrogen solubility was lowest at pH of 4.0 and 9.0, respectively, with maximum solubility occurring at pH of 6.0. Defatting increased the water absorption and fat absorption capacities of Moringa oleifera kernel flour. The foaming capacity and foam stability of the defatted flour were 86.0% and 82.0 mL, whereas that of full‐fat flour were 20.6% and 18.5 mL respectively. The defatted flour showed better emulsification (97.2 mL g^?1) than full‐fat flour (66.0 mL g^?1). The least gelation concentration of the defatted and full‐fat flours was 14% and 16% (w/v) respectively. Moringa oleifera kernel flour can be a valuable source of vegetable protein in fortified food products formulation.     

Prediction of linolenic and linoleic fatty acids content in flax seeds and flax seeds flours through the use of infrared reflectance spectroscopy and multivariate calibration

Infrared spectroscopy was used for multivariate determination of linoleic (LA) and linolenic (ALA) acids in yellow and brown flax seed samples, using partial least square regression (PLSR). The models were developed by correlating near-(NIR) and mid-infrared (MIR) spectroscopic signals with the acid content determined by GC-FID. For the flax seed samples, the best models for both, LA (R² = 0.90, Standard Error of Prediction (SEP) = 1.61) and ALA (R² = 0.86, SEP = 0.63) were obtained by processing the NIR spectral data. For samples of flax seed flours, the best models for prediction of the ALA (R² = 0.99, SEP = 1.21) and LA content (R² = 0.88, SEP = 0.76) were developed by processing the NIR and MIR spectral region, respectively. This report demonstrates that NIR and MIR spectroscopies are efficient techniques for the determination and quantification of LA and ALA in flax seed and flax seed flours.     

Effect of rice variety,rice flour concentration and enzyme levels on composite bread quality

A study was conducted to determine the suitability of substituting portions of wheat flours with rice flours for breadmaking. The levels of substitution were 50, 100, 150 and 200 g kg^?1. Two kinds of enzymes, barley malt and fungal amylase, were added to composite flours, and their effects on the volume and quality of the rice-based bread were determined. The results showed that the enzymes, levels of replacement and the varieties of rice had significant effects on weight, specific volume and overall acceptability of the bread samples. However, the enzymes did not have significant effects on the volume, protein and fat contents or on the character and color of the crust in the sensory analysis. Comparisons were made of the nutritional and sensory qualities of the bread made entirely from wheat flour, and the sample which performed best, the bread with 50 g kg^?1 of flour from low amylose variety (183.3 g kg^?1) with barley malt, showed non-significant differences. The overall acceptability of the products showed that it is acceptable to substitute wheat flour with flours generated from rice up to the 150 g kg^?1 replacement level only.     

Sarcoplasmic Protein Profile from Drip Loss in Relation to Pork Quality

The aim of this research was to correlate the sarcoplasmic protein profile of the natural drip loss of muscle with the technological and sensory quality of pork meat. Material for analysis was taken from 14 PenArLan pigs. Simple analysis of relationships between the test protein and meat quality traits showed that they adopt a range of from –0.58 to 0.72. It has been shown that the significance of glycolysis expressed as level of glycogen and lactic acid may be 86% (coefficient of correlations, C_R = 0.93), explained by the amount of certain enzymes. The higher relation has been obtained between studied enzymes and value of pH₂₄, L^* and b^* parameters of raw meat (98%; C_R = 0.99). By contrast, L^* and a^* parameters, sour flavor, and tenderness of grilled meat in 79% can be explained based on the content of the enolase, glyceraldehyde‐3‐phosphate dehydrogenase, and phosphoglycerate mutase (C_R = 0.89). The results of the multiple regression showed that amount of lactic acid was related to the quantity of the 3 enzymes: phosphofructokinase, AMP deaminase, phosphorylase b/phosphorylase b kinase (r = 0.88).     

Functional and Thermal Properties of Wheat, Barley, and Soy Flours and Their Blends Treated with a Microbial Transglutaminase

The effects of transglutaminase (TG) on the functional and thermal properties of wheat, barley, and soy flours and their blends were investigated. Free amino and thiol groups and aromatic hydrophobicity in samples were decreased with TG treatment (P < 0.05), confirming the polymerization of proteins in flours by TG treatment. TG‐treated samples had increased water‐holding capacity, fat adsorption, and emulsion stability, and slightly decreased emulsion activity. The addition of barley or soy to wheat flours decreased fat adsorption and emulsion stability, but these values increased, upon TG treatment of the same blended samples, to levels as high as for untreated wheat alone. TG treatment did not significantly affect the transition peak temperature of the flour samples. However, TG treatment lowered the transition enthalpy of wheat blended with barley or soy flour, and, conversely, increased that of wheat flour samples alone. Results suggest that protein cross‐linking by TG can produce unique and improved functionality even in wheat blended with barley or soy flour, and could provide opportunities for exploitation of this enzyme for product development.     

Quality of dried white salted noodles affected by microbial transglutaminase

To examine the potential application of microbial transglutaminase (MTGase) in oriental noodle making, the effects of various MTGase addition levels on the rheological, textural and structural properties of noodles were investigated using good quality (‘Red Bicycle’) and poor quality (‘Sandow’) wheat flours. Addition of MTGase at 5–20 g kg^?1 levels, but not at 1 g kg^?1 level, to the two different wheat flours decreased rapid visco‐analyser (RVA) parameters of hot paste viscosity and final viscosity while increasing breakdown. For fresh white salted noodle dough sheets, the storage modulus (G′) and loss modulus (G″) increased significantly at 1 g kg^?1 MTGase addition for both types of flour, but there was no clear trend with higher levels of MTGase. For dried white salted noodles, textural parameters (tensile force, hardness and gumminess) generally increased, cooking loss was little affected and the yield of the cooked noodle was significantly decreased by MTGase. Color was slightly adversely affected. Scanning electron microscopy (SEM) results indicated that physical properties of dry noodles were improved through the formation of cross‐links [ε‐(γ‐glutamyl)lysine] by MTGase. Copyright © 2005 Society of Chemical Industry     

Chemometrics coupled with ultraviolet spectroscopy: a tool for the analysis of variety,adulteration, quality and ageing of apple juices

This study demonstrates the use of UV spectroscopy (UV) in combination with chemometrics as a simple and feasible approach for analysis of variety, adulteration, quality and ageing of apple juice. The results show that PCA‐UV is adequate to differentiate apple juice varieties and adulteration. The percentage of the adulterant can be detected by PLSR‐UV with RMSE < 0.7783% and R² > 0.9980. For the evaluation of juice quality, PLSR‐UV (RMSE = 0.2555–2.3448; R² = 0.7276–0.9816) is recommended for the prediction of soluble solids, ascorbic acid, total flavonoids, total sugar and reducing sugar, whilst PCR‐UV (RMSE = 0.0000–2.7426; R² = 0.7073–1.0000) is adequate for the prediction of pH and antioxidant activity. In addition, PLSR‐UV may be used to predict the storage time with RMSE = 0.4681 day and R² = 0.9832. Therefore, UV coupled with chemometrics has potential to be developed as a portable tool for the detection of variety, adulteration, quality and ageing of not only apple juices, but also other fruit and vegetable juices.     

Structural development of sucrose‐sweetened and sucrose‐free sponge cakes during baking

The influence of sucrose, wheat starch and sorbitol upon the heat‐ and mass‐exchanging processes forming the structure of sponge cake was studied. Under the influence of wheat starch and sorbitol the structure of the sucrose‐free sponge cake was formed at more uniform total moisture release. This process was done at lower temperatures and smoother change of the sponge cake height with respect to the sucrose‐sweetened sponge cake. The porous and steady structure of both cakes was finally formed at identical time – between 18^th and 19^th minute, at the applied conditions for baking of each batter (metal pan with diameter 15.4 cm and depth 6.2 cm containing 300 g of batter and placed in an electric oven “Rahovetz – 02”, Bulgaria for 30 min at 180°C). The water‐losses at the end of baking (10.30% and 10.40% for the sucrose‐sweetened cake and sucrose‐free cake, respectively) and the final temperatures reached in the crumb central layers (96.6°C and 96.3°C for the sucrose‐sweetened cake and sucrose‐free cake, respectively) during baking of both samples were not statistically different. The addition of wheat starch and sorbitol in sucrose‐free sponge cake lead to the statistically different values for the porosity (76.15% and 72.98%) and the volume (1014.17 cm³ and 984.25 cm³) of the sucrose‐sweetened and sucrose‐free sponge cakes, respectively. As a result, the sucrose‐free sponge cake formed during baking had a more homogeneous and finer microstructure with respect to that of the sucrose‐sweetened one.     

Proximate analysis of homogenized and minced mass of pork sausages by NIRS

Near infrared spectroscopy was employed to analyse samples of pork sausage meat used in the manufacturing of typical Spanish sausages (minced and homogenized product). As well, two modes of analysis for the instrument were compared. Data from proximate analysis (fat, moisture and protein) were put into a calibration model by a diode array NIR spectrometer. The spectral range used was 515–1650 nm and different mathematical pre-treatments on the signal (derivatives and scatter corrections) were also compared. Different mathematical pre-treatments caused considerable changes in the statistics of the models (coefficients of determination and standard errors). R² (calibration) and standard errors of prediction (SEP, external validation) in minced sausage meat for fat, moisture and protein were 0.98, 0.98 and 0.93 (R²) and 1.38%, 1%, 0.83% (SEP), respectively. These values in homogenised sausage meat for fat, moisture and protein were 0.99, 0.98 and 0.93 (R²), and 0.94%, 0.76% and 0.87% (SEP), respectively.     

Accuracy of near infrared spectroscopy for prediction of chemical composition, salt content and free amino acids in dry-cured ham

The capability of near infrared (NIR) spectroscopy was examined for the purposes of quality control of the traditional Slovenian dry-cured ham “Kraški pršut.” Predictive models were developed for moisture, salt, protein, non-protein nitrogen, intramuscular fat and free amino acids in biceps femoris muscle (n = 135). The models' quality was assessed using statistical parameters: coefficient of determination (R²) and standard error (se) of cross-validation (CV) and external validation (EV). Residual predictive deviation (RPD) was also assessed. Best results were obtained for salt content and salt percentage in moisture/dry matter (R_CV² > 0.90, RPD > 3.0), it was satisfactory for moisture, non-protein nitrogen, intramuscular fat and total free amino acids (R_CV² = 0.75–0.90, RPD = 2.0–3.0), while not so for protein content and proteolysis index (R_CV² = 0.65–0.75, RPD < 2.0). Calibrations for individual free amino acids yielded R_CV² from 0.40 to 0.90 and RPD from 1.3 to 2.9. Additional external validation of models on independent samples yielded comparable results. Based on the results, NIR spectroscopy can replace chemical methods in quality control of dry-cured ham.