The influence of different packaging materials and atmospheric conditions on the properties of pork rinds

Rancidity development in high fat content products is a common off-flavor flaw in snack foods. Packaging is often used to avoid spoilage and extend shelf-life. The properties of pork rinds packaged in four different packaging materials with and without nitrogen were studied during 120 days of storage (22 °C, RH 60%, absence of light). The influence of different packaging materials and atmospheric conditions on pork rinds’ water activity, hardness, crispness and rancidity development was determined. The PET/PE packaging material had lower barrier properties for the product in both atmospheric conditions compared with PP/metPP (40 and 50 μm) and PET/PETmet/PE. PP/metPP 50 and PET/PETmet/PE with nitrogen atmospheres were demonstrated to be the most suitable packaging materials for pork rinds

Effect of quality properties of added gluten on the texture and sensory properties of rye and buckwheat breads

Received: February 11th, 2023 ; Accepted: July 13th, 2023 ; Published: September 10th, 2023 ; Correspondence: [email protected] producers use vital wheat gluten to enhance the quality of their products. However, commercial isolated glutens could have different properties and therefore influence the properties of the final products. As studies on the quality properties of glutens and their effect on the final baking products are limited, the aim of this study was to characterize commercial isolated glutens and the effect of their addition on the textural and sensory properties of rye and buckwheat breads. Three glutens were tested for water binding capacity (WBC), gluten index (GI), protein sedimentation, and resistance using modified methods. Afterwards, three different bread recipes were developed and commercial glutens were tested in each model bread. The commercial glutens had different physicochemical and viscoelastic properties, which were below the typical values of native glutens (GI was 36‒46%, extensibility- 48‒78 mm). Breads also had different sensorial and textural properties, which diverged more during storage. The sour taste intensity and springiness of the rye bread increased, while its moistness, adhesiveness, and typical odour intensity decreased. Fresh and staled rye toast breads were softer and more porous. The buckwheat bread was the most stable, though it was drier and springier after storage. The effect of gluten was specific to the bread recipe and was uncorrelated with the gluten quality properties individually. However, gluten with the intermediate values of WBC, sedimentation, and extensibility, also resulted in breads with intermediate sensory properties. Thus, it is possible to enhance specific properties of bread using commercial glutens with different quality attributes

The Composition, Physicochemical Properties, Antioxidant Activity, and Sensory Properties of Estonian Honeys

Thirty honey samples from different regions of Estonia were investigated to determine the chemical compositions, physicochemical properties, bioactive compounds, and sensory characteristics of typical honeys from a northern climate. The physicochemical parameters, such as electrical conductivity, moisture content, free acidity, hydroxymethylfurfural, diastase, and invertase activity were measured. The color was measured and expressed by L*-, a*-, and b*-coordinates. Sensory parameters were determined by using “fruity”, “floral”, “berry-like”, “herbal”, “woody”, “spicy”, “sweet”, and “animal-like” as the main odor and flavor attributes. The total polyphenol and flavonoid contents were in the range of 26.2–88.7 mg gallic acid equivalents (GAE) per 100 g and 1.9–6.4 mg quercetin equivalents (QE) per 100 g, respectively. The identified polyphenols showed the highest intensities of caffeic acid, coumaric acid, and abscisic acid and its derivatives. The protocatechuic acid intensity was highest in honeys containing traces of honeydew elements and of cinnamic acid and myricetin in heather honey. The water-soluble antioxidant values were 37.8–311.2 mg ascorbic acid equivalents (AAE) per 100 g and the lipid soluble antioxidant values were 14.4–60.7 mg Trolox equivalents (TE) per 100 g. The major amino acid in the analyzed honeys was proline, with variable values depending on the honey’s botanical source. Correlations were calculated based on the results obtained. It was revealed that the typical Estonian honey has floral, berry-like, sweet, and rather mild sensory characteristics. Most of the honeys lacked stronger spicy, woody, and animal-like attributes. The typical color of Estonian honey is quite light

Toiduainete tehnoloogia

KõrgkooliõpikToiduainetööstus annab suure osa Eesti rahvuslikust koguproduktist ja on toidu tooteahelas (toore-töötlemine-turustus) kõige olulisemaks lisandväärtuse loojaks. Sellele vaatamata puudub senini eestikeelne toiduainete tehnoloogia kõrgkooliõpik, mis sisaldaks süsteemselt esitatud baasteadmisi: • loomse- ja taimse toorme omadustest, koostisest jms, • toidutoorme töötlemise füüsikalis-keemilistest ja bioloogilistest põhiprotsessidest, • olulisemate toiduainete tehnoloogiatest. Eestikeelne toiduainete tehnoloogia õppekirjandus on senini lünklik, käsitleb eraldi kitsaid teemasid ega moodusta ühtset tervikut. See asjaolu raskendab üliõpilaste õppetööd, spetsialistide täiendkoolitust ja üldiste töötlemispõhimõtete tutvustamist ka laiemalt toidu tooteahelas. Koostatud õpik on mõeldud eelkõige toiduainete tehnoloogia alaste baasteadmiste omandamiseks bakalaureuseõppes ja edaspidi jääb aluseks praktiliste õppevormide (labortööd, praktikumid) ning erinevate e-õppe materjalide, õppevideote jms süsteemsel väljatöötamisel. Õpiku olemasolu võimaldab suurendada toiduainete tehnoloogia bakalaureuseõppe üliõpilaste iseseisva töö mahtu ja muuta kogu õppeprotsessi efektiivsemaks. Selleks, et toiduainete valmistamine toimuks efektiivselt, on vajalik tunda nii toidutoorme koostist ja omadusi kui võimalikke töötlemise meetodeid ja tehnilisi lahendusi. Koostatav õpik on vajalik infoallikas ka toiduainete tööstustele, kuna toiduainete töötlemine (tehnoloogia) on suhteliselt keeruline, mitmekülgseid baasteadmisi eeldav valdkond. Peale selle soodustab õpik ühtse eestikeelse erialaterminoloogia juurdumist ning on kasulik infoallikas vastavatele hobirühmadele ja toiduainete tarbijatele kui toidu tooteahela sihtgrupile

The Nonequilibrium Phase and Glass Transition Behavior of β-Lactoglobulin

Concentrated solutions of bovine β-lactoglobulin were studied using osmotic stress and rheological techniques. At pH 6.0 and 8.0, the osmotic pressure was largely independent of NaCl concentration and could be described by a hard sphere equation of state. At pH 5.1, close to the isoelectric point, the osmotic pressure was lower at the lower NaCl concentrations (0 mM, 100 mM) and was fitted by an adhesive hard sphere model. Liquid-liquid phase separation was observed at pH 5.1 at ionic strengths of 13 mM and below. Comparison of the liquid-liquid and literature solid-liquid coexistence curves showed these solutions to be supersaturated and the phase separation to be nonequilibrium in nature. In steady shear, the zero shear viscosity of concentrated solutions at pH 5.1 was observed at shear rates above 50 s(−1). With increasing concentration, the solution viscosity showed a progressive increase, a behavior interpreted as the approach to a colloidlike glass transition at ∼60% w/w. In oscillatory shear experiments, the storage modulus crossed the loss modulus at concentrations of 54% w/w, an indication of the approaching glass transition. Comparison of the viscous behavior with predictions from the Krieger-Dougherty equation indicates the hydrodynamic size of the protein decreases with increasing concentration, resulting in a slower approach to the glass transition than a hard sphere system