In this study, various kinds of cryoprotectant (skim milk, lactose, and sucrose) formulations were tested to enhance the survival of Lactobacillus brevis ED25 after freezing and freeze‐drying. A Box–Behnken experimental design was used to optimize cryoprotective medium and the highest cell survival was observed with the 17.28% skim milk, 2.12% lactose, and 10% sucrose cryoprotectant as the optimum condition. The structural and physicochemical characteristics of freeze‐dried powder were acceptable for application with regards to particle surface morphology, moisture and water activity (Aw), glass transition temperature (Tg), Fourier transform infrared spectra, X‐ray structure, and also storage stability under the refrigeration and room temperature conditions. Accelerated storage test based on Arrhenius equation could be used to predict the freeze‐dried bacterial shelf life but only with a certain degree of predictability for long‐term storage. The acidification kinetics of fresh and stored culture in sourdough fermentation was also described on the basis of the Gompertz equation. Practical applications Freezing and storage are crucial factors for the viability and acidification power of starter culture. Therefore, various types and concentrations of cryoprotectants have been used to preserve the microorganisms. L. brevis ED25 has been a good potential for the manufacture of industrial sourdoughs and this research has aimed to investigate long‐term protective effects of optimum cryoprotectant formulations on the viability of bacteria and also determine the acidification power in sourdough. The results showed the potential value of freeze‐dried L. brevis ED25 culture for commercialization.

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Hazelnut, an important source of nutrition, is reasonably expensive for hazelnut milk production. Hazelnut cake, a by-product from hazelnut oil production by cold press extraction technique, does not contain any chemical residue and can be used for hazelnut beverage production. This study investigates the effects of thermosonication process on the quality parameters of hazelnut milks and also compares the observed results with the conventional thermal process. Different thermosonication conditions at different amplitude levels (40 and 60% amplitudes for 5, 10, 15, 20 and 25 min and 80% amplitude for 3, 5, 10 and 15 min) were studied for physicochemical and rheological properties, as well as microbial inactivation and bioactive compounds of hazelnut milk produced from the cold pressed hazelnut cake as byproduct of oil production. In general, sonication process significantly improved the total phenolic compounds, antioxidant activity, appearance and structural properties like syneresis, sedimentation, viscosity and consistency of samples. The application of thermosonication at 60% amplitude for 25 min and 80% amplitude for 15 min achieved complete inactivation of microorganisms (total aerobic mesophilic bacteria and yeast-mould). Complete inactivation of microorganisms was also achieved by conventional pasteurization at 85°C, but this treatment caused some undesirable changes such as loses of bioactive compounds and deterioration of structural properties. The findings of the present study indicate that thermosonication can be successfully utilized for commercial processing of hazelnut milk with improved quality. This technique allows the production of hazelnut milks in safety and quality standards with highly nutritious then the conventional product.

Plant-derived proteins, such as those from sesame seeds, have the potential to be used as versatile food ingredients. End-use functionality can be further improved by high-intensity ultrasound treatments. The effects of high-intensity ultrasound on the properties of sesame protein isolates from cold-pressed sesame cake were evaluated. The SDS-PAGE demonstrated no significant changes in the molecular weight of proteins. Ultrasound treatments resulted in decreased particle size with a more uniform distribution, resulting in the exposure of hydrophobicity and free −SH groups and increased zeta potential. Although FTIR spectra of proteins were similar after ultrasonication, a partial increase in the intensity of the amide A band was observed. The ultrasound significantly (p < 0.05) affected the secondary structure of proteins. While optical micrographics revealed a dispersed structure with smaller particles after treatments, microstructural observations indicated more rough and irregular surfaces. Water solubility was improved to 80.73% in the sample subjected to 6 min of ultrasonication. Sesame protein solutions treated for 4 and 6 min exhibited viscoelastic structure (storage modulus (G′) > loss modulus (G′′)). In addition, the gelation temperature of proteins decreased to about 60–65 °C with increasing treatment time. Overall, ultrasound is a useful technique for the modification of sesame protein isolates.

In this study, essential oil from sucuk spice mix was incorporated into poly(lactic) acid (PLA) and nano bers were produced via solution blow spinning (SBS). Essential oil incorporation was performed at 0, 5, 10, 15, 20, 25 and 30% (v/w) of PLA. Scanning electron microscopy (SEM), atomic force microscopy (AFM), thermal properties, antioxidant capacity, and antibacterial activity against E. coli and S. aureus were characterized. Nano bers were not soluble in water due to the hydrophobic nature of PLA. SEM images revealed that beadles and uniform nano bers can be produced with SBS, and essential oil addition decreased the average ber diameter. The surface topography of nano bers was improved by increasing essential oil concentration. Melting and glass transition temperatures decreased and the thermal stability of nano bers increased with essential oil addition. Nano bers containing essential oil at 30% had the highest antioxidant capacity (40.02%). Nano bers containing 20, 25, and 30% of essential oil had greater growth inhibition against Staphylococcus aureus and Escherichia coli. As a result, PLAbased nano bers containing sucuk spice mix essential oil can be produced with SBS, and nano bers containing 20, 25, and 30% essential oil could be a promising system not only in drug delivery systems but also in food packaging. HighlightsPoly(lactic acid) nano bers with essential oil were produced by solution blow spinning.Nano bers showed antimicrobial activity and antioxidant capacity.Average ber diameter decreased with increasing essential oil concentration.Melting and glass transition temperature of nano bers decreased.Increasing essential oil content improved the surface topography of nano bers.

This study aimed to investigate the influence of microwave drying with different power levels as alternative to convective drying method on drying kinetics and main quality attributes of hawthorn slice. At increasing microwave power values, higher drying rate and shorter drying time was observed. The page model was found to give best fit (R 2 > 0.9961, RMSE < 0.028 and χ 2 < 0.675x10 -3 ) for all drying treatments. Although the minimum change of color and texture value were obtained at microwave power of 600 W, the convective drying caused less total color and texture change depending fresh sample. Drying process at microwave powers of 600 W and 360 W showed the best quality in terms of rehydration and bioactive properties, respectively. The findings in current work demonstrated that microwave drying at 360 W microwave power might be suitable for drying of hawthorn slices with high quality and bioactive properties as well as low operating costs.

In this study, the effects of various matrices consisting of maltodextrin and reconstitute skim milk and their binary and ternary mixtures with gum Arabic in the microencapsulation of Lactobacillus casei Shirota by freeze-drying technique were assessed. Microcapsules produced with reconstitute skim milk showed high viability (>99%) after freeze drying. While the free cells were completely inactivated after exposure to simulated gastrointestinal conditions, the survival rates of microencapsulated L. casei Shirota were found high for all microcapsules except for maltodextrin and maltodextrin:gum Arabic formulas. The viability of microencapsulated L. casei Shirota during storage at refrigerate and room temperatures decreased between 0.39 and 2.43 log cycles and microcapsules produced with reconstitute skim milk:gum Arabic was found more durable at the both storage conditions. Reduction in the number of free cells was higher than encapsulated L. casei Shirota numbers during production of dessert, however the viability of encapsulated L. casei Shirota was found stable for 14 days of storage and consequently desserts containing encapsulated L. casei Shirota (except maltodextrin) showed stable pH values. This study revealed that combination of reconstitute skim milk:gum Arabic was an effective wall matrix for microencapsulation of L. casei Shirota by freeze drying and also very resistant against gastrointestinal fluids and storage conditions in view of protection of L. casei Shirota.

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