Decreasing Water Activity Research Articles

Effect of Flavourzyme on proteolysis, antioxidant activity and sensory qualities of Cantonese bacon

The aim of this study was to investigate the influence of Flavourzyme on protein degradation, antioxidant activity and sensory qualities of Cantonese bacon made at 60°C for 28h. Flavourzyme was used at doses of 8, 16, 24, 32 and 40LAUP/kg of raw meat. Results indicated that Flavourzyme addition in Cantonese bacon promoted proteolysis, which was reflected by the increase of various free amino acids and SDS-PAGE-detected changes in the myogen and myofibrillar proteins. Sensory qualities were improved while TPA (texture profile analysis) was decreased significantly (P<0.05). The best sensory scores were obtained at between 24 and 32LAPU/kg. Besides, Flavourzyme addition improved antioxidant activity, and decreased water activity and protein carbonyl content of Cantonese bacon. This study indicated that the addition of Flavourzyme improved eating attributes and storage stability of Cantonese bacon.

Surface tension prevails over solute effect in organic-influenced cloud droplet activation.

The spontaneous growth of cloud condensation nuclei (CCN) into cloud droplets under supersaturated water vapour conditions is described by classic Köhler theory. This spontaneous activation of CCN depends on the interplay between the Raoult effect, whereby activation potential increases with decreasing water activity or increasing solute concentration, and the Kelvin effect, whereby activation potential decreases with decreasing droplet size or increases with decreasing surface tension, which is sensitive to surfactants. Surface tension lowering caused by organic surfactants, which diminishes the Kelvin effect, is expected to be negated by a concomitant reduction in the Raoult effect, driven by the displacement of surfactant molecules from the droplet bulk to the droplet-vapour interface. Here we present observational and theoretical evidence illustrating that, in ambient air, surface tension lowering can prevail over the reduction in the Raoult effect, leading to substantial increases in cloud droplet concentrations. We suggest that consideration of liquid-liquid phase separation, leading to complete or partial engulfing of a hygroscopic particle core by a hydrophobic organic-rich phase, can explain the lack of concomitant reduction of the Raoult effect, while maintaining substantial lowering of surface tension, even for partial surface coverage. Apart from the importance of particle size and composition in droplet activation, we show by observation and modelling that incorporation of phase-separation effects into activation thermodynamics can lead to a CCN number concentration that is up to ten times what is predicted by climate models, changing the properties of clouds. An adequate representation of the CCN activation process is essential to the prediction of clouds in climate models, and given the effect of clouds on the Earth's energy balance, improved prediction of aerosol-cloud-climate interactions is likely to result in improved assessments of future climate change.

Effect of Freezing Rate and Microwave Thawing on Texture and Microstructural Properties of Potato (Solanum tuberosum).

Food freezing is a preservation process that works by lowering temperature while simultaneously decreasing water activity. It is accepted that although freezing preserves foods, it generally has a negative effect on textural quality. This research investigated the texture response of potatoes (Solanum tuberosum) as a function of time to freeze (defined as the time for the center temperature to reach -20 °C) and thawing process. Potatoes slices (6 mm) were blanched then frozen in an ethanol/carbon dioxide bath, a pilot scale high velocity air freezer (HVAF) and a still air freezer to achieve various times to freeze. Slices were stabilized at -20 °C and thawed by 2 methods; room temperature air and microwave. Afterwards, samples were allowed to come to room temperature prior to texture profile analysis (TPA). Results indicate a maximum texture loss of the potato was reached at a time to freeze of approximately 8 min (corresponding to the HVAF). The texture difference between room temperature and microwave thawing methods was not shown to be significant (P = 0.05). SEM images showed the cellular structure of the potato in a HVAF to be similar to that of the still air freezer, validating that the matrix was maximally damaged in both conditions. This work created a continuous quality loss model for the potato as a function of time to freeze and showed no textural benefit to high velocity over still air freezing.

Clean Foods: The Inhibitory Effect of Five Natural Juices on the Browning of Apple Slices during Drying

Enzymatic browning, which accompanies food preservation processes based on drying, is a common obstacle to obtaining marketable and consumer-appealing products. In this paper, we investigate the application of one of the methods commonly used in order to counter the browning process, namely dipping. Dipping involves a soaking of the foods in liquids or solutions in order to suppress the activity of polyphenoloxidase (PPO) enzymes, either by physically preventing oxygen from interacting with it, or by dramatically decreasing water activity and thus slowing down water-dependent reactions. In this study, juices from selected fresh fruits with high ascorbic acid content were used as natural preservatives with antibrowning effects. The juices were prepared from fruit of the following species: Sorbus aucuparia, Diospyros kaki, Hippophae rhamnoides, Actinidia deliciosa, and Rosa canina. The effect of selected juices on color change was tested on dried “Idared” apple slices and was compared to slices of freshly cut apples (standard). The browning index of all sample groups showed significant differences between treatment groups and the standard except for samples treated with Rosa canina juice. The effect of the juices was also evaluated via a sensory panel, where color change, degree of browning, change of taste, and overall acceptability of the resulting color and taste were evaluated. Results showed that the best antibrowning effect was achieved by macerate from fruits of Rosa canina. The results of this study showed that dipping in some plant juices has the potential of complementing or replacing the sulphite-based approach, which is the current method of choice of the food industry.

AVALIAÇÃO DA ESTABILIDADE DE GELEIAS DE AMORA-PRETA ACONDICIONADAS EM DIFERENTES EMBALAGENS

The blackberry jam has a high potential for industrialization, in order that the fruit has a fragile structure, high perishability, and high respiratory activity. This study evaluated the stability of blackberry jams packed in glass and polypropylene at temperature (25 ± 2oC) in light conditions and refrigerated temperature (4oC ± 2oC) for 120 days. The physico and chemical characteristics were analyzed: water activity, soluble solids, titratable acidity, pH, total anthocyanins and the content of vitamin C. It was observed that the quality of jams was influenced by the type of packaging and the storage time, which committed the nutritional characteristics of the product. The results showed a decrease in water activity, the levels of anthocyanins and vitamin C with the time of storage, however, the glass packaging showed better values for the maintenance of the physico-chemical characteristics jams been contribute to maintaining the shelf-life of the product.

Diffusion through Pig Gastric Mucin: Effect of Relative Humidity.

Mucus covers the epithelium found in all intestinal tracts, where it serves as an important protecting barrier, and pharmaceutical drugs administrated by the oral, rectal, vaginal, ocular, or nasal route need to penetrate the mucus in order to reach their targets. Furthermore, the diffusion in mucus as well as the viscosity of mucus in the eyes, nose and throat can change depending on the relative humidity of the surrounding air. In this study we have investigated how diffusion through gels of mucin, the main protein in mucus, is affected by changes in ambient relative humidity (i.e. water activity). Already a small decrease in water activity was found to give rise to a significant decrease in penetration rate through the mucin gel of the antibacterial drug metronidazole. We also show that a decrease in water activity leads to decreased diffusion rate in the mucin gel for the fluorophore fluorescein. This study shows that it is possible to alter transport rates of molecules through mucus by changing the water activity in the gel. It furthermore illustrates the importance of considering effects of the water activity in the mucosa during development of potential pharmaceuticals.

Predicting the kinetics of Listeria monocytogenes and Yersinia enterocolitica under dynamic growth/death-inducing conditions, in Italian style fresh sausage

Traditional Italian pork products can be consumed after variable drying periods, where the temporal decrease of water activity spans from optimal to inactivating values. This makes it necessary to A) consider the bias factor when applying culture-medium-based predictive models to sausage; B) apply the dynamic version (described by differential equations) of those models; C) combine growth and death models in a continuous way, including the highly uncertain growth/no growth range separating the two regions.This paper tests the applicability of published predictive models on the responses of Listeria monocytogenes and Yersinia enterocolitica to dynamic conditions in traditional Italian pork sausage, where the environment changes from growth-supporting to inhibitory conditions, so the growth and death models need to be combined. The effect of indigenous lactic acid bacteria was also taken into account in the predictions.Challenge tests were carried out using such sausages, inoculated separately with L. monocytogenes and Y. enterocolitica, stored for 480h at 8, 12, 18 and 20°C. The pH was fairly constant, while the water activity changed dynamically. The effects of the environment on the specific growth and death rate of the studied organisms were predicted using previously published predictive models and parameters.Microbial kinetics in many products with a long shelf-life and dynamic internal environment, could result in both growth and inactivation, making it difficult to estimate the bacterial concentration at the time of consumption by means of commonly available predictive software tools. Our prediction of the effect of the storage environment, where the water activity gradually decreases during a drying period, is designed to overcome these difficulties. The methodology can be used generally to predict and visualise bacterial kinetics under temporal variation of environments, which is vital when assessing the safety of many similar products.

Spray Drying of Tamarind Pulp: Effect of Process Parameters Using Protein as Carrier Agent

This study investigated the effect of soya protein isolate (SPI) and inlet air temperature on various properties of spray dried tamarind pulp powder. Increase in SPI concentration and inlet temperature significantly increased powder recovery from 17.90 to 55.07% and 52.54 to 59.60%, respectively. Increase in SPI concentration and inlet temperature significantly increased solubility from 49.90 to 71.58% and 59.82 to 65.22%, respectively. Higher values for particle size (90.65 µm; 77.63 µm) and lower values for cohesion index (8.46 mm; 9.29 mm) were observed at higher SPI concentration and inlet temperature. Increase in SPI concentration significantly decreased water activity, bulk density and DPPH radical scavenging activity of spray dried powder from 0.168 to 0.140, 0.52 to 0.45 g/mL and 61.91 to 45.81%, respectively. At higher inlet temperature low values of water activity (0.148), bulk density (0.48 g/ml) and radical scavenging activity (51.42%) were observed. Micrographs of powder samples showed wrinkled morphology. Practical Applications Soya protein isolate (SPI) due to its surface active and film forming property can be used for the production of quality spray dried tamarind pulp powder with increased powder yield and considerably reduces the requirement of higher concentration of carrier agents like maltodextrin, and gum Arabic for powder production, which otherwise would lead to alteration of the powder quality and risks consumer disapproval. Moreover, among the process variables related to spray drying, the inlet air temperature can be considered very important, since it is directly related with powder quality. Thus, in the present study, the effect of protein concentration and inlet air temperature on the physicochemical properties of spray-dried tamarind pulp was investigated. The results can be helpful for food companies looking for production of quality tamarind pulp with high powder recovery.

Texture Quality of Candied Fruits as Influenced by Osmotic Dehydration Agents

AbstractCandied fruits produced with healthier ingredients for obtaining low glycemic index, low energy and/or dietary fiber enriched products were develop by substituting the traditionally used osmotic dehydration sugars sucrose and glucose by fructose, sorbitol, maltitol, fructooligosaccharides and galactooligosaccharides. Quality of candied fruits was evaluated chemically, rheologically and sensorially. For all fruits the final composition was dependent on the osmotic dehydration agent used and, in all cases, the final composition show that fruits can be impregnated successfully with the healthier ingredients.Each of the different osmotic dehydration agents significantly influenced the texture and sensorial profile of the candied fruits, but the changes were dependent on the fruits, with the texture and sensorial quality of some products being better and other poorer than the commercial candied fruits. For all fruits tested, the osmotic dehydration agent sorbitol imprinted peculiar characteristics. The chemical composition of the final products show that candied fruits obtained with these alternative osmotic dehydration agents are suitable healthier alternatives of the traditional candied fruits. Still, only a consumer's trial would assess the palatability of the different fruits/osmotic dehydration agents tested.Practical ApplicationsOne of the main objectives of food processing is the preservation of perishable foods. Candying of fruits results in a decrease of water activity by osmotic dehydration, prolonging fruits shelf‐life. This process changes the textural and sensorial properties but also has an impact on its dietary value, due to sucrose and glucose used in candying, accused for being responsible for various illness. Therefore, the candying industry is looking for substitutes, those so called “healthy ingredients” that can be used for osmotic dehydration and yield products with similar or even better quality properties (structural, textural and organoleptic). Fructose, sorbitol, maltitol, and dietary fiber oligosaccharides, are possible candidates for substitution of sucrose in the candying industry. With this work we aim to increase the knowledge about modifications at the textural and sensorial level occurring on these fruits after the candying process to adequately control candying and improve the quality of candied fruits.

Prebiotics as protectants of lactic acid bacteria

The important role of lactic acid bacteria in the food and pharmaceutical industries highlights the requirement of appropriate preservation processes. During these processes, the decrease of water activity is the main cause of damage to the bacterial structures, cell membranes being the first target of this damage. To avoid this, using protective compounds becomes mandatory, polyhydroxylated ones being the most widely used. Prebiotics are mostly nondigestible oligosaccharides. Then, why not to use them as protectants?

How Inhomogeneous Salt Distribution Can affect the Sensory Properties of Salt‐Reduced Multi‐Component Food: Contribution of A Mixture Experimental Design Approach Applied to Pizza

AbstractSalt reduction in food is a major concern for public health authorities but remains a challenge for the food industry. Aims of this study are to modulate salt distribution between the ingredients of salt‐reduced pizza (−30%) by modifying the salt content of each ingredient without changing the total salt content of pizza using mixture experimental design, to demonstrate its impact on sensory properties, and to determine the formulation with sensory properties, evaluated by Quantitative Descriptive Analysis, closest to the reference product. In this study, pizzas are made of dough, ham, cheese and sauce in constant proportions. Obtained results underline the consequences of modulating salt distribution on perception of multi‐component foods. The distribution of salt between ingredients affects taste and texture perception and predictive models are established for each discriminating attributes. An optimal formulation, determined by multi‐response analysis, is found with sensory properties closest to the reference product allowing compensating salt reduction. This formulation is composed of 20% of salt from cooked ham, 47.5% from mozzarella‐style cheese, 0% from dough and 32.5% from tomato sauce. Salt should thus be located preferentially within mozzarella‐style cheese and tomato sauce whereas it can be extensively reduced in dough.Practical ApplicationsIn addition to being used as a taste and flavour enhancer, salt is involved in (1) food preservation by decreasing water activity; (2) in food structure by modifying the protein network and interactions between proteins and components of food; and (3) in the variation of enzyme activity This is why, reducing the salt content in food products without affecting their organoleptic properties constitutes a major challenge for the manufacturers. This work presents the feasibility of modulating salt distribution between ingredients of salt‐reduced pizza (−30%) by modifying the salt content of each ingredient without changing the total salt content of pizza as an efficient way to maintain sensory perceptions as reference product allowing compensating salt reduction.

Effects of microwave roasting on physicochemical properties of pistachios (Pistaciavera L.)

Effects of 480 and 640 W power levels and 2, 3 and 4 min for roasting of pistachios using microwaves (MW) on the physicochemical properties of pistachios in comparison with an Iranian traditional method of soaking in salty water and drying under hot-air at 135°C for 20 min were investigated. MW roasting of pistachios decreased water activity values, producing a softer nut. Twenty one volatile compounds were identified in roasted pistachios using GC-MS. The highest volatile concentration and sensory odor intensity scores were observed for hot air roasted pistachios and MW at 640 W for 4 min. Roasting reduced the force needed to cut pistachios. Unsaturated fatty acid contents in MW roasted pistachios were higher (82.0%) than in hot-air produced nuts (74.7%). Total phenolic content values increased with roasting time and with the MW power level. Pistachios can be successfully roasted using microwaves as a fast and economical method.

Effect of Partial Replacement of Sucrose With Humectant in the Osmotic Solution on the Characteristics of Osmo-Dried Cantaloupe

ABSTRACTThe effect of osmotic solutions consisting of sucrose and humectants (sorbitol and glucose syrup) on the quality of osmo-dried cantaloupe was investigated. The ratios between sucrose and each humectant were varied (90:10, 80:20, and 70:30). The increments in water loss and solid gain were observed with increasing the sorbitol ratio in the mixtures, while increasing the glucose syrup ratio in the mixture decreased water loss and solid gain during osmotic dehydration. All samples immersed in the osmotic solution containing sucrose and sorbitol had higher L* and lower a* values than those of samples immersed in the osmotic solution containing sucrose and glucose syrup. The hardness tended to decrease with increasing sorbitol and glucose syrup ratio in the osmotic solution. In addition, the increment of all humectants ratios caused a decrease in water activity (aw). The reduction in vitamin C, phenolic content, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity was observed with increasing sorbitol concentration in the osmotic solution. Moreover, an increase in all humectant ratios could reduce 5-hydroxymethylfurfural content in the final product. The sensory attributes, including color, texture, and overall acceptability, were found to be better in the case of sucrose-sorbitol treated samples when compared to those of the sucrose-glucose syrup treated samples.

Effect of Solvent Activity on Solute Association: The Formation of Aqueous Nickel(II) Chloride Complexes Studied by UV–Vis and EXAFS Spectroscopy

Water activity is generally considered to affect ionic association in aqueous electrolyte solutions; however, it is usually ignored when the association reactions or constants are discussed. In this work, the effect of water activity on the association reaction $$ {\text{Ni}}_{{ ( {\text{aq}})}}^{2 + } + n{\text{Cl}}_{{ ( {\text{aq)}}}}^{ - } \rightleftharpoons {\text{NiCl}}_{{n{\text{ (aq)}}}}^{2 - n} $$ was investigated by EXAFS and UV–Vis spectroscopy measurements on NiCl2 aqueous solutions at room temperature with constant Cl−/Ni2+ ratio (~66) and various water activities; the latter were adjusted by adding MgCl2 and Mg(ClO4)2. Both the EXAFS and the UV–Vis spectra measurements indicated that the extent of Ni–Cl association increases in decreasing water activity environments, independent on the Cl−/Ni2+ ratio. Thus, the effect of water activity on the ionic association should not be ignored and more emphasis should be paid on it, especially, when the water activity is very low.

Forsterite dissolution rates in Mg‐sulfate‐rich Mars‐analog brines and implications of the aqueous history of Mars

AbstractHigh salinity brines, although rare on Earth's surface, may have been important in the geologic history of Mars. Increasing evidence suggests the importance of liquid brines in multiple locations on Mars. In order to interpret the effect of high ionic strength brines on olivine dissolution, which is widely present on Mars, 47 new batch reactor experiments combined with 35 results from a previous study conducted at 25°C from 1 &lt; pH &lt; 4 in magnesium sulfate, sodium sulfate, magnesium nitrate, and potassium nitrate solutions with ionic strengths as high as 12 m show that very high ionic strength brines have an inhibitory effect of forsterite dissolution rates. Multiple linear regression analysis of the data suggests that the inhibition in dissolution rates is due to decreased water activity at high ionic strengths. Regression models also show that mMg up to 4 m and mSO4 up to 3 m have no effect on forsterite dissolution rates. The effect of decreasing dissolution rates with decreasing aH2O is consistent with the idea that water acts as a ligand that participates in the dissolution process. Less available water to participate in the dissolution reaction results in a slower dissolution rate. Multiple linear regression analysis of the data produces the rate equation . Forsterite in dilute solutions with a water activity of one dissolves twice as fast as those in brines with a water activity of 0.8.

The Influence of Protonation on the Electroreduction of Bi (III) Ions in Chlorates (VII) Solutions of Different Water Activity

We examined the electroreduction of Bi (III) ions in chlorate (VII) solutions under varied protonation conditions of the depolariser using voltammetric and impedance methods. The results of the kinetic parameter correlation lead to the statement that the changes in the amount of chloric (VII) acid against the amount of its sodium salt in the supporting electrolytes of the low water activity have a significant influence on the rate of Bi (III) ion electroreduction. The increase of the concentration of chloric acid sodium salt, as well as the chloric (VII) acid alone within the particular concentration of the supporting electrolyte, inhibits the process of Bi (III) ion electroreduction. It should be associated with the reorganisation of the structure of the double layer connected with the slow dehydration inhibited by ClO 4− ions. The standard rate constants ks values with the increase of the chlorate (VII) concentrations for all the solutions examined of chlorates (VII) confirms the catalytic influence of the decrease of water activity on the process of Bi (III) ion electroreduction. The multistage process is confirmed by the non-rectilinear 1nkf = f(E) dependences.

Effect of High Hydrostatic Pressure on Salmonella Inoculated into Creamy Peanut Butter with Modified Composition

Peanut butter has been associated with several large foodborne salmonellosis outbreaks. This research investigates the potential of high hydrostatic pressure processing (HPP) for inactivation of Salmonella in peanut butter of modified composition, both by modifying its water activity as well by the addition of various amounts of nisin. A cocktail of six Salmonella strains associated with peanut butter and nut-related outbreaks was used for all experiments. Different volumes of sterile distilled water were added to peanut butter to increase water activity, and different volumes of peanut oil were added to decrease water activity. Inactivation in 12% fat, light roast, partially defatted peanut flour, and peanut oil was also quantified. Nisaplin was incorporated into peanut butter at four concentrations corresponding to 2.5, 5.0, 12.5, and 25.0 ppm of pure nisin. All samples were subjected to 600 MPa for 18 min. A steady and statistically significant increase in log reduction was seen as added moisture was increased from 50 to 90%. The color of all peanut butter samples containing added moisture contents darkened after high pressure processing. The addition of peanut oil to further lower the water activity of peanut butter further reduced the effectiveness of HPP. Just over a 1-log reduction was obtained in peanut flour, while inactivation to below detection limits (2 log CFU/g) was observed in peanut oil. Nisin alone without HPP had no effect. Recovery of Salmonella after a combined nisin and HPP treatment did show increased log reduction with longer storage times. The maximum log reduction of Salmonella achieved was 1.7 log CFU/g, which was comparable to that achieved by noncycling pressure treatment alone. High pressure processing alone or with other formulation modification, including added nisin, is not a suitable technology to manage the microbiological safety of Salmonella-contaminated peanut butter.

Water-fluxed melting of the continental crust: A review

Abstract Water-fluxed melting, also known as fluid- or water-present melting, is a fundamental process in the differentiation of continents but its importance has been underestimated in the past 20 years during which research efforts focused mostly on dehydration melting reactions involving hydrate phases, in the absence of a separate aqueous phase. The presence of a free aqueous phase in anatectic terranes influences all major physical and chemical aspects of the melting process, from melt volumes, viscosity and ability to segregate from rock pores, to melt chemical and isotopic composition. A review of the literature shows that melting due to the fluxing of aqueous fluids is a widespread process that can take place in diverse tectonic environments. Active tectono-magmatic processes create conditions for the release of aqueous fluids and deformation-driven, transient high permeability channels, capable of fluxing high-temperature regions of the crust where they trigger voluminous melting. Water-fluxed melting can be either congruent in regions at the water-saturated solidus, or incongruent at suprasolidus, P–T conditions. Incongruent melting reactions can give rise to peritectic hornblende, or to nominally anhydrous minerals such as garnet, sillimanite or orthopyroxene. In this case, the presence of an aqueous phase is indicated by a mismatch between the large melt fraction generated and the much smaller fractions predicted in its absence. The relatively small volumes of aqueous fluids compared to that of rocks imply that melting reactions are generally rock buffered. Fluids tend to move upwards and down temperature. However, there are cases in which pressure gradients drive fluids up temperature, potentially fluxing suprasolidus terranes. Crustal regions at conditions equivalent to the water-saturated solidus represent a natural impediment to the up-temperature migration of aqueous fluids because they are consumed in melting reactions. In this case, continued migration into supra-solidus terranes take place through the migration of water-rich melts. Thus, melts become the transport agent of water into supra-solidus terranes and responsible for water-fluxed melting. Other processes, such as the relatively rapid fluid migration through fractures, also allow regional aqueous fluids to by-pass the water-saturated solidus fluid trap and trigger melting above solidus conditions. When aqueous fluids or hydrous melts flux rocks at supra-solidus conditions, they equilibrate with the surroundings through further melting, decreasing water activity and giving rise to undersaturated melts. It is in these conditions that hornblende or anhydrous peritectic phases are stabilized. Unlike dehydration melting, the melt fraction generated in this case is not limited by the water contained in hydrous minerals but by the volume of water added to the system. Unlike melting at the water-saturated solidus, these melts are capable of rising without freezing and do give rise to upper crustal granitic bodies.

MicroglassificationTM: A Novel Technique for Protein Dehydration

The dehydration of biologics is commonly employed to achieve solid-dose formulation and enhanced stability during long-term preservation. We have developed a novel process, Microglassification™, which can rapidly and controllably dehydrate protein solutions into solid amorphous microspheres at room temperature. Single bovine serum albumin (BSA) microdroplets were suspended in pentanol or decanol using a micropipette, and the dynamic changes in droplet dissolution were observed in real-time and correlated to protein's water of hydration, medium's water activity, and microsphere protein concentration. Microglassification™ was also carried out at bulk scale, and changes in BSA secondary structure were analyzed by Fourier transform infrared spectroscopy and fluorescence spectroscopy; multimer formation was detected by native gel electrophoresis. BSA concentration in the microsphere increased with solvent exposure time and decreasing water activity. Image analysis at single particle and bulk scale showed the formation of solid BSA microspheres with a maximum protein concentration of 1147 ± 32 mg/mL. The native BSA samples were dehydrated to approximately 450 waters per BSA, which is well below monolayer coverage of 1282 waters per BSA. The secondary structure of Microglassified™ BSA reverted to native-like conformation upon rehydration with only minor irreversible aggregation (2.7%). Results of the study establish the efficacy of the Microglassification™ for the successful dehydration of biologics.

Effect of autochthonous starter cultures isolated from Siahmazgi cheese on physicochemical, microbiological and volatile compound profiles and sensorial attributes of sucuk, a Turkish dry-fermented sausage

The effect of adding autochthonous starter cultures isolated from Siahmazgi cheese, on the physicochemical parameters and microbial counts of sucuk was investigated during the ripening period. SPME–GC/MS was used in volatile compound analysis and a trained group of panelists carried out sensory analysis of the final product. After preliminary screening, three strains of Lactobacillus plantarum, which possess desirable technological properties, were used to prepare three starter cultures: LBP7, LBP10 and LBP14. The addition of LBP7 and LBP14 starter cultures had a significant effect (P<0.05) on lightness, leading to higher L values compared to control sausages during the ripening period. Both LBP7 and LBP14 sausages showed higher counts of lactic acid bacteria, lower growth of Enterobacteriaceae and Gram-positive catalase-positive cocci and greatly lowered the pH value compared to control sausages throughout the ripening process. At the end of the ripening process, lactic acid bacteria counts were affected (P<0.05) by the addition of starter culture since higher counts were observed in sausages prepared with LBP7 (9.14logCFU/g) and LBP14 (8.96logCFU/g) batches. The decrease of water activity during the ripening of sausages was not affected by the various starters. The texture profiles of all sausages were similar except for LBP10, which showed lower hardness and gumminess during ripening. Under the conditions of the study, volatile compounds were mainly from spices, and no marked differences were found among inoculated sausages. However, sensory evaluation revealed that most of the sensory attributes were scored higher for inoculated sausages than for the control ones. Therefore, LBP7 and LBP14 could be promising candidates for inclusion as starter cultures for the manufacture of sucuk.