Physical and textural properties of biscuits containing jet milled rye and barley flour.

The biscuit-making performance of flour depends on both its botanical source and particle size. Several quality parameters of biscuits produced by partial replacement of wheat flour by barley and rye flours at 0, 10, 20, 30 and 40% were measured. Moreover, in order to investigate the effect of particle size, a commercial and two jet milled finer samples of both rye and barley flours were used. For most of the composite flours, the level of substitution was not statistically significant for the weight and the spread ratio of the biscuits. Biscuits with composite flours were softer and darker than the control biscuit (100% wheat flour). In addition, their total phenolics content and antioxidant activity were greater. Among composite flour biscuits, the finer barley flour biscuits were harder than those with the commercial flour. Moreover, as rye flour is darker than wheat and barley flours, rye biscuits were the darker of all. Porosity, bulk and true densities were affected by the particle size of the substitute flours.

Properties of Sweet Buttermilk Released from the Churning of Cream Separated from Sheep or Cow Milk or Sheep Cheese Whey: Effect of Heat Treatment and Storage of Cream.

The objective of the study was to compare the buttermilk released from the churning of sweet cream separated from sheep milk (BSM) or whey (BSW) with the buttermilk from sweet cow milk cream (BCM). Additional experimental factors were the heat treatment (68 °C for 10 or 30 min) and storage of cream (refrigeration or freezing). The composition of BSM was the most advantageous in terms of non-fat solids, protein-which was the most abundant solid component-casein, calcium and phosphorus contents. No significant differences were observed in the phospholipids (PL) content of BSM, BCM and BSW. Antioxidant potential and emulsion stability (ES) of BSM were the highest. The radical scavenging activity (RSA) of BSW was high opposite to chelating activity (CA). Some functional properties of BSW were similar to those of BSM and BCM. The freezing of cream affected the churning, the fat content, the soluble nitrogenous fraction at pH 4.6 (WSN) and some functional properties of buttermilk, but not in a consistent manner. The properties of BSM were marginally affected or unaffected by the use of frozen cream. The freezing of whey cream caused significant changes (p < 0.05) in the protein profile and the functional behaviour of BSW. Cream heat treatment affected the WSN of BSW opposite to its sweet cream counterparts.

Encapsulation of EGCG and esterified EGCG derivatives in double emulsions containing Whey Protein Isolate, Bacterial Cellulose and salt.

Double (W1/O/W2) emulsions of 0.8 %wt PGPR-0.25 %wt BC-1 %wt WPI and NaCl (1.6-8 %wt) were characterized regarding their microstructure, droplet size, stability and viscosity. Droplet size increased with salt concentration. Salt addition at 4-5% wt limited the instability rate. Viscosity increased with NaCl concentration up to 4.8 %wt, above which it decreased. Eventually, the emulsion with 4.3 %wt salt was selected for catechin incorporation. In order to increase its antioxidant activity, Epigallocatechin Gallate (EGCG) was esterified with stearic acid. Esterification was partial and a mixture of esters was obtained. Both EGCG and its esterified derivatives were incorporated in the double emulsion. Storage reduced encapsulation. Encapsulation efficiency was reduced in the order "EGCG in the W1 phase" emulsion > "EGCG in the O phase" emulsion > "esterified EGCG in the W1 phase" emulsion. The presence of both catechins did not have a great effect on retarding emulsion oxidation.

Sodium alginate-cinnamon essential oil coated apples and pears: Variability of Aspergillus carbonarius growth and ochratoxin A production.

The scope of the present study was to use selected fruits as model foods (wounded skin or slices of apples and pears), for the in situ assessment of the potential of natural antimicrobials to control fungal growth and OTA production and the investigation of alternative ways of their application, e.g., via edible coatings. Fresh fruits were cut: i) in halves or ii) across in round slices of ca. 1 cm thickness. Wounds were introduced into the skin and the center of the slice (5 mm deep; 4 mm diameter) and inoculated with a range of 2.0-7.5 × 103spores per wound of Aspergillus carbonarius. Following inoculation, samples were coated with Na - alginate supplemented with 0.3 (0.3% ECC) and 0.9% v/v (0.9% ECC) cinnamon ΕΟ. Inoculated samples without edible coating and EO (C) or with edible coating and without EO (EC) were used as negative or positive controls, respectively. All samples were stored under aerobic conditions at 15, 20, and 25 °C. Fungal growth was estimated by colony diameter measurements (n = 30), while OTA production was determined by HPLC (n = 4). Antimicrobial treatment with 0.9% EO was more effective on fungal growth when the inoculation took place on slices than in wounded skin (p < .05), regardless of storage temperature and fruit. The variability of µmax increased with EO concentration, except for the coated slices of apples with 0.9% v/v EO (at all temperatures), or pears with 0.3% and 0.9% v/v EO (at 15 and 20 °C), where no growth was observed. OTA was below the detection limit (1 ppb) on the majority of 0.9% ECC apples slices and in 0.3% ECC and 0.9% ECC pears slices, stored at 20 and 25 °C. However, the sample to sample variation in the produced amounts of OTA was remarkable. Thus, considering that inhibition of growth and toxin production do not always concur, the present study provided quantitative information on the variability in A. carbonarius growth and OTA production in real model foods in response to antimicrobial coating with natural active compounds. Such data could be of relevance to risk assessment and assist in designing effective control strategies for limiting OTA levels in foods and thus, protecting consumer health.

Properties of flour films as affected by the flour's source and particle size.

Wheat (W) and rye flour (R, R1 and R2) films were developed. The rye flours used differed in their particle size. R1 and R2 resulted from jet milling of the R flour at two different feed rates. The mean particle size of W, R, R1 and R2 flours was 173.87, 100.91, 54.59 and 35.66 µm, respectively. Glycerol was used as plasticizer at concentrations of 0.5, 0.7 and 1 g/g of flour. Films made from mixtures of flours (50:50 w/w) were also studied in the presence of 0.7 g glycerol/g of flour. Colour, moisture content, solubility, thickness, viscosity, microstructure and mechanical properties were assessed. In most cases the films were homogeneous. Film moisture content, thickness, opacity and mechanical properties were correlated to glycerol concentration. Particle size was found important for the mechanical properties. Wheat films were lighter ([L*] ≈ 49) and less opaque (135). For both single and composite films, moisture content varied from 24 to 35%, solubility from 43.5-58%, opacity from 135 to 371, thickness from 0.66-0.72 mm and mechanical strength from 0.68-1.7 MPa. All film-forming solutions exhibited shear thinning behaviour. Wheat flour dominated most of the studied properties in composite films. Rye films were more opaque, with relatively high solubility but greater mechanical strength.

Limonene encapsulation in freeze dried gellan systems.

The encapsulation of limonene in freeze-dried gellan systems was investigated. Surface and encapsulated limonene content was determined by measurement of the absorbance at 252nm. Gellan matrices were both gels and solutions. For a standard gellan concentration (0.5wt%) gelation was induced by potassium or calcium chloride. Furthermore, gellan solutions of varying concentrations (0.25-1wt%) were also studied. Limonene was added at two different concentrations (1 and 2mL/100g sample). Gellan gels encapsulated greater amounts of limonene than solutions. Among all gellan gels, the KCl gels had the greater encapsulated limonene content. However, when the concentration of limonene was doubled in these KCl gels, the encapsulated limonene decreased. The surface limonene content was significant, especially for gellan solutions. The experimental conditions and not the mechanical properties of the matrices were the dominant factor in the interpretation of the observed results.

Influence of jet milling and particle size on the composition, physicochemical and mechanical properties of barley and rye flours.

Finer barley and rye flours were produced by jet milling at two feed rates. The effect of reduced particle size on composition and several physicochemical and mechanical properties of all flours were evaluated. Moisture content decreased as the size of the granules decreased. Differences on ash and protein contents were observed. Jet milling increased the amount of damaged starch in both rye and barley flours. True density increased with decreased particle size whereas porosity and bulk density increased. The solvent retention capacity profile was also affected by jet milling. Barley was richer in phenolics and had greater antioxidant activity than rye. Regarding colour, both rye and barley flours when subjected to jet milling became brighter, whereas their yellowness was not altered significantly. The minimum gelation concentration for all flours was 16%w/v. Barley flour gels were stronger, firmer and more elastic than the rye ones.

Bioactivity of Epigallocatechin Gallate Nanoemulsions Evaluated in Mice Model.

The hypothesis that incorporation of epigallocatechin gallate (EGCG) into nanoemulsions may increase its bioactivity compared with EGCG aqueous solutions was examined in mice. After an in vitro study in a model system with stimulated gastrointestinal conditions, the following EGCG nanoemulsions were used in a mice experiment: Emulsion I: emulsion water in oil (W/O), which contained 0.23 mg/mL EGCG in aqueous phase; Emulsion II: emulsion oil in water (O/W), which contained 10% olive oil and 0.23 mg/mL esterified EGCG in fatty phase; and Emulsion III: emulsion O/W in water (W1/O/W2; 8:32:60), which contained 32% olive oil and 0.23 mg/mL EGCG in aqueous phase. After 2 h of mice administration by gavage with 0.1 mL of EGCG nanoemulsions, total antioxidant capacity (TAC) of plasma and some tissues (especially colon, jejunum, heart, spleen) was measured with Ferric-Reducing Antioxidant Power (FRAP) and Oxygen Radical Absorbance Capacity (ORAC) assays. No toxic effects were observed after administration of 0.23 mg/mL esterified EGCG in CD1 mouse strain. The study concluded that administration of mice with the three EGCG nanoemulsions did not increase their TAC in specific tissues, compared with an aqueous EGCG solution at the same concentration. Nevertheless, the esterified EGCG emulsion (Emulsion II) exerted an increase in mice plasma compared with aqueous EGCG and showed higher values of TAC in several tissues, compared with Emulsions I and III. EGCG nanoemulsions could be considered a useful method in plethora functional food applications, but further research is required for safer results.

The effect of sugars on the retention of ethyl butyrate by gellan gels.

The effect of sucrose, glucose and fructose on the retention of ethyl butyrate by low acyl gellan gels was investigated by static headspace gas chromatography. The air/biopolymer partition coefficient (K) and percentage of retention (R%) were determined. When 5 g of sample were left to equilibrate at 37 °C for 24 h, the obtained results were explained in terms of gel rigidity, as increased rigidity resulted in increased aroma retention. Glucose showed the greatest aroma release among the sugars and resulted in either the same or increased aroma release with increasing concentration. Increasing concentrations of fructose and sucrose did not alter aroma release significantly. For 15 g of sample mass, sucrose exhibited the lowest partition coefficient values among the sugars. The two higher sucrose concentrations resulted in decreased coefficient values. For fructose and glucose, aroma retention decreased with increasing concentration. The percentage of retention values were positive for all sugars, throughout their concentration range and for both experiments.