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关键词： Rabbit meat composition   Heat treatments   Scanning electron micrographs   Color evaluation   Fat oxidation   Sensory attributes  

摘要： This study investigated the effect of five different cooking methods (boiling, oven-roasting, grilling, pan-frying and microwave) on the topographical changes, fatty acids (FAs) profile, fat oxidation, physicochemical characteristics, microbial quality, and sensory attributes of rabbit meat. Among the cooking methods, boiling and pan-frying exhibited significant higher protein, fat and total volatile base nitrogen contents. Additionally, boiling induced the lowest fat oxidation and FAs saturation values, while microwave cooking induced the highest values. Boiling and microwave cooking received the lowest appearance, color and flavor scores, while grilling- and microwave-cooking obtained the highest tenderness and juiciness scores, along with the lowest shear force values. This study is the first concerning the topographical structure of cooked rabbit meat using the scanning electron micrographs, which revealed minimal destructive changes in muscle fibers and connective tissue in panfried cooked samples and greatest destructive effect in grilling-cooked samples. Oven-roasting is the best cooking method since it achieved both the health benefits and consumer acceptability.

关键词： Pasteurization   Vibrio   Colour   Adductor muscle   Pinctada fucata  

摘要： This study investigated the effect of 5-20 min low-temperature pasteurization at 50 degrees C on Akoya oyster's physicochemical including moisture, texture, colour, pH, total volatile base nitrogen (TVB-N) and microbiological quality in terms of total viable count (TVC), tests for Escherichia coli (E. coli), Vibrio spp. and Vibrio parahaemolyticus (V. parahaemolyticus) 14 days post-treatment. Oysters were sourced from Abrolhos island pearl farm and kept alive in simulated condition until treatment day. Physicochemical analyses and TVC were then conducted on day 0, 4, 7, 10, 14 while the remaining microbiological analyses were performed on day 0, 7, 14. Regression analysis showed that none of physicochemical characteristics showed a linear trend, with the exception of TVB-N which increased linearly in all treated oyster with increasing the storage time. Two-way ANOVA indicated that heat treated oysters with more than 10 min treatment time shown to have increase in moisture and firmness compare to control. Colour improvement was also observed in >10 min heat treated adductor muscle while no consistent changes in pH were observed. TVB-N value ranging from 11.49 to 23.59 mg/100 g was influenced by treatment and storage time with significant increases identified in all samples at day 10 and 14. The microbiological results reveal that, TVC, E. coli and V. parahaemolyticus were within standard limit and considered safe to be consumed. Additionally, heat treatment of more than 10 min has shown to suppress Vibrio spp. growth until day 7-14. General amelioration in Akoya oysters physicochemical and microbiological quality suggests that low-temperature pasteurization is a viable option in Akoya oyster processing. Results could aid in commercialization of raw Akoya oyster product and waste reduction in pearl industries.

关键词： Starch   Green algae   Rheological properties   Amylose   Retrogradation   Digestibility  

摘要： Edible green marine macroalgae, especially species of Ulva, can accumulate starch up to 30% of their dry weight;however, its physicochemical, functional, and digestibility properties are still unknown. In this study, we characterized molecular mass distribution, amylose-amylopectin ratio, crystallinity, hydration capacity, visco-elastic and pasting properties, and the digestibility of starch extracted from Ulva ohnoi and compared it to rice and potato starches. Ulva starch had a higher amylose content than rice and potato starches (55.0%, 34.5% and 24.3%, respectively). Ulva starch exhibited higher hydration capacity than rice starch (25.7 gwater/gstarch and 10.3 gwater/gstarch respectively), while potato starch exhibited the highest hydration capacity, of 41 gwater/gstarch, probably mainly due to presence of phosphate groups. Ulva starch had the lowest mass-average molecular weight ((1.17x10(6) g/mol), compared to rice (4.40x10(6) g/mol) and potato (5.80x10(6) g/mol) starches. Ulva starch exhibited the highest G' and viscosity setback ratio after cooling-induced gelation following gelatinization, probably thanks to its uniquely high amylose content, which led to higher tendency for physical crosslinking by retrogradation. This may also explain the fact that Ulva starch exhibited somewhat lower digestibility after retrogradation, compared to rice and potato starches, which would be advantageous for forming resistant starch serving as a dietary fiber, and lowering glycemic index. The superior gel properties on the one hand and lower digestibility, which would be helpful in tackling obesity & diabetes, on the other hand, make Ulva starch a unique and promising new functional food ingredient.

关键词： bovine milk   heat stability   ethanol stability   milk composition   milk processing composite and  

摘要： The value of milk hinges on its physicochemical func-tionality under processing conditions. We examined composition-functionality relationships with individual milks from 24 New Zealand dairy cows, sampled at 3 times over the season. Milks were classified into type A or B, according to the shape of 3-point heat coagulation time versus pH profiles. Milk type changed over the season for half of the cows in the study. Best subsets regression suggested that different factors controlled heat stability in the 2 milk types. Urea concentration was key for both types, but for type A milks, osmotic pressure and milk solids were the most important pre-dictors of heat stability, whereas casein micelle size and ionic calcium predicted heat stability for type B milks. This study revealed that milk type is prone to change over the season, and the findings suggest that optimiz-ing heat stability could be achieved by different means for type A versus type B milks.

关键词： Robinia pseudoacacia   Plectranthus rugosus   Multifloral honey   Physico-chemical   Antioxidant   FTIR-ATR spectroscopy  

摘要： Three types of honeys viz. Robinia pseudoacacia (RSA), Plectranthus rugosus (PR) and multifloral honey (MF) from Kashmir Himalayas of India were characterized on the basis of physicochemical, antioxidant and FTIR-ATR spectroscopic features. The physicochemical parameters indicated that ash content, electrical conductivity, redness (a*) and yellowness (b*) were higher in MF honey, moisture content, Hydroxymethylfurfural (HMF) and lightness (L*) in PR honey and Water activity (a(w)) and proline content in RSA honey (P <= 0.05). Significantly higher values of total sugar, total reducing sugar and sucrose content was observed in MF honey (P <= 0.05). The total phenolic content (TPC), total flavonoids, ferric reducing antioxidant power and 1, 1-diphenyl-2-picrylhydrazy-IC50 (DPPH-IC50) free radical scavenging activity showed that MF honey had significantly higher antioxidant activity (P <= 0.05). ATR-FTIR analysis demonstrated that the absence of peaks at broad band around 1653.454-1637.656 cm(-1) in MF honey, 1185.989-1153.072 cm(-1) and 918.570-916.544 cm(-1) wavenumbers in PR honey thus clearly discriminating different types of honeys. The results revealed that physico-chemical, antioxidant and spectroscopic characteristics of honey types vary with geographic origin and their floral sources and MF honey have a high therapeutic potential.

关键词： Chitosan   Tripolyphosphate   Nanoparticles CS-TPP   Ionic gelation   Antibacterial activity  

摘要： Chitosan (CS) nanoparticles with antibacterial properties have been synthesized by the ionic gelation method using tripolyphosphate (TPP) as a crosslinking agent. Physicochemical properties of the resulting CS-TPP nanoparticles were examined by FTIR spectroscopy, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray, transmission electron microscopy, and UV-Vis spectroscopy. The antibacterial efficacy of the nanoparticles against S. aureus and E. coli was evaluated by the disc diffusion (DD) method. It was found that the optimum conditions for fabricating the CS-TPP nanoparticles were: pH of 2.85, CS concentration of 1.5 mg/ml, TPP concentration of 0.5 mg/ml, CS:TPP feed ratio of 1:1, mixing speed of 300 rpm, and reaction temperature of 30 degrees C. The CS-TPP nanoparticles decreased in average particle size with an increase in the CS concentration. Based on the DLS results, the average size of CS-TPP ranged from 79.2 to 114.2 nm, with a polydispersity index of 0.369-0.398. However, slightly larger sizes were observed (150 to 180 nm), based on the TEM and SEM images. The CS-TPP has more regular structures compared to CS, indicated by the increase of crystallinity based on X-ray diffraction patterns. In addition, FTIR spectra confirmed that interactions in tripolyphosphate were predominantly between CS amines and TPP counterions via ionic interactions, as supported by SEM-EDX. CS-TPP exhibited antibacterial activity. The highest inhibition zone radius was 5.0 and 5.5 mm against E. coli and S. aureus, respectively. The bio-based materials have a high potential for use as value-added antibacterial agents.

关键词： Fruit juice   Concentration   Solar energy   Quality characteristics  

摘要： The preservation of the quality characteristics of fruit juices during the processing is one of the major challenges in the fruit juice industries. The high costs of fossil fuels and their environmental pollution increased the need to use of the renewable energies. In the present study, some quality characteristics of barberry juice were investigated during concentrating by the methods of liquid desiccant-assisted solar juice concentration system (LD-ASJCS) at the air flow rates of 0.006-0.014 kg/s, rotary vacuum evaporation system (RVES), and evaporation at atmospheric pressure (EAP). Although evaporation rate in LD-ASJCS increased by 25% with increasing of air flow rate from 0.006 to 0.014 kg/s, but it had negative effects on some quality properties of concentrated juices. The anthocyanins retention in the concentrated juices with different air flow rates of LD-ASJCS method were 16-28%. Reduction of the air flow rate resulted in a lower browning index and less variation of color indices (L*, a*, and b*). The a* values, browning index, and sensory attributes of the concentrated juices in the LD-ASJCS at the air flow rate of 0.006 kg/s were comparable to the concentrated juices by the RVES method. Although, RVES method compared to EAP and LD-ASJCS methods better improved the quality of barberry juice, but the LD-ASJCS method can be considered in fruit juice industries because of maintaining quality and sensory attributes, saving energy, and reducing environmental pollution. The mathematical modelling of physicochemical changes of LD-ASJCS concentrated juice showed that these variations are fitted with first-order and zero-order models.

关键词： Gum Arabic   Gelatin   Microencapsulation   Olive paste   Thyme essential oil  

摘要： In this study, thyme essential oil (TEO), a natural antimicrobial and antioxidant substance, was encapsulated by a complex coacervation method using gum Arabic and gelatin as wall material and tannic acid as a crosslinking agent. The quality characteristics of the olive paste samples, which were aimed to be increased by adding TEO (1000 mg/kg) and TEO microcapsules, were determined at 4 degrees C and 25 degrees C during the storage period of 56 days. Physico-chemical, sensory, and antioxidant activity analyses were performed on all olive paste samples during the storage period. The thymol and carvacrol contents of the enriched olive paste samples were quantified by high-performance liquid chromatography (HPLC). The enrichment of olive paste samples with microencapsulated TEO resulted in an increase in sensory properties with the total dry matter, color scores (L*, a*, and b*), total phenolic content, thymol, and carvacrol content, while a decrease in peroxide value and total mesophilic aerobic bacteria content. The results showed that the microcapsule structure preserved TEO during storage, the antioxidant activity of olive paste samples enriched with TEO microcapsules increased, and thus, the enriched olive paste could be stored in a safer and higher quality than control samples. Therefore, using microcapsules containing TEO in olive paste samples may be a suitable method to produce functional foods with antioxidant properties.

关键词： Urban aerosol   Atmospheric particulate matter   Size and morphology of particles   Chemical composition of particles   Microorganisms in aerosols   Aerosol health impact  

摘要： Eight aerosol samples were collected in Krakow using a low-volume sampler in February and March 2019 during variable meteorological conditions and times of the day, to study their single particles' properties (size, morphology and chemical composition analyzed using a scanning electron microscope fitted with an energy-dispersive spectrometer) and microbiological characteristics. The content of particles of different chemical compositions larger than 2.5 mu m was low. Considering the number of the particles, submicron particles strongly dominated with a high content of ultrafine particles (nanoparticles). Tar ball-type particles were relatively common in the studied samples, while soot was the dominant component. Soot was present as small agglomerates composed of few particles, but also as bigger agglomerates. Metal-containing particles of various chemical characteristics were abundant, with transition metals commonly occurring in these particles. The physicochemical characteristics of aerosols indicate that despite a relatively low mass concentration, their adverse health impact could be very strong because of the high content of nanoparticles, the abundance of soot and other fuel combustion-related particles, and the high incidence of transition metal-rich particles. Microbiological analysis was based on cultures on both solid and liquid agar. The MALDI-TOF method was used for species identification-for bacteria and fungi. Twelve different species of bacteria were isolated from the collected samples of aerosols. The most frequently isolated species was Gram-positive sporulating Bacillus licheniformis. The isolated mold fungi were of the genus Aspergillus.

关键词： Cellulose   dietary fibres   fat replacer   sausage   sugarcane bagasse  

摘要： The potential of cellulose from sugarcane bagasse used for pork sausage was investigated. The purity level of cellulose fibre from sugarcane bagasse and the functional characteristics in pork sausage were studied. The differences in the sugarcane fibre and sausage characteristics were strongly related to the cellulose/lignin content of the extracted cellulose under different amounts of bleaching. Bleached sugarcane fibres showed better water (3.55) and oil (2.34) holding capacity in comparison with untreated fibre (2.92 and 2.38, respectively). The sugarcane fibres in each treatment stage showed different effects on sausage properties. Sausages with 1% cellulose fibres added had an improved texture profile, but the addition of 3% cellulose fibres to sausages resulted in a higher cooking yield. Consumers considered the sensory characteristics of all sausages as acceptable. These results indicated that low levels of cellulose extracted from sugarcane bagasse could be added and maintain the inherent characteristics of meat products.