Physical and chemical characteristics of Asian sea bass bio-calcium powders as affected by ultrasonication treatment and drying method

The effects of ultrasonication and drying method on particle size and other product characteristics of bio-calcium powder from Asian sea bass (Lates calcarifer) backbone were investigated. Ultrasonication was performed at different amplitudes (60%, 70%, and 80%) for varying periods (15 and 30 min). Ultrasonication at higher amplitudes for a longer time reduced the powder particle size more effectively (p < .05), but had no impact on zeta potential (p > .05). The bio-calcium powder ultrasonicated at 70% amplitude for 15 min had the smallest particle size (3.38 µm) when compared to the control (28.85 µm). When the ultrasonicated bio-calcium was subjected to drying, freeze-drying produced powders with higher calcium solubility but lower whiteness than hot air (tray) drying. The results suggest that the ultrasonication is a potential suitable method to reduce the size of bio-calcium powders, while the drying method slightly affected the product characteristics. The bio-calcium powder could serve as a suitable functional ingredient for food fortification aimed at improving the calcium bioavailability. Particle size of bio-calcium powder from fishbone could affect the mouth feel and calcium solubility when used for food product fortification. This work showed that ultrasonication could be used to obtain up to 10-fold reduction in the particle size of fishbone bio-calcium powders, which promotes increased calcium solubility when subjected to simulated gastrointestinal tract digestion. Few differences in characteristics of the bio-calcium powder were observed for freeze-dried and hot air-dried samples. Thus, an economical, safe, and fast process can be implemented for the production of small particle size bio-calcium powder from fishbone.     

Ball milling improves extractability and antioxidant properties of the active constituents of mushroom Inonotus obliquus powders

Inonotus obliquus has been used as a folk remedy for a long time. An improved method using fine grinding by ball mill was investigated, and the main chemical components and physicochemical properties of Inonotus obliquus powders were analysed. The Inonotus obliquus fine grinding powders were prepared by pulverising the coarse powder with planetary ball mill for different time. The results showed that the yields of polysaccharides increased from 41.08 mg g^?1 (coarse powder) to 319.62 mg g^?1, and the yields of polyphenols were also increased fourfold in ball‐milled powders as compared to the untreated one. Ball‐milled powders showed higher values in the bulk density, angles of repose and slide, water solubility index and swelling capacity (P < 0.05), but lower values in the water‐holding capacity and oil‐holding capacity. The shape and surface morphology of the powders were changed after ball mill treatment. The antioxidant properties of the extracts from ball‐milled powders were significantly improved (P < 0.05). The results will be helpful for the application of Inonotus obliquus in food and pharmaceutical industries.     

Effects of hydroxyl radical induced oxidation on water holding capacity and protein structure of jumbo squid (Dosidicus gigas) mantle

Protein oxidation is considered as an important issue in food preservation process. In the present study, the potential influence of protein oxidation on water holding capacity and protein structure of jumbo squid (Dosidicus gigas) mantle was investigated. After the hydroxyl radical oxidation, it was found that the carbonyl, surface hydrophobicity and dityrosine content of myofibrillar protein significantly increased (P < 0.05), while the content of total sulphydryl decreased significantly (P < 0.01). Meanwhile, the fluorescence intensity of squid was weakened, and the maximum absorption peak of fluorescence red shift as the H₂O₂ concentration increased. The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that not only the protein cross-linking but also degradation could have occurred. The content of α-helix decreased, the content of β-sheet, β-turn and the unordered structures increased after oxidation. In addition, oxidation resulted in a decrease in water holding capacity. Taken together, oxidation resulted in the damage of the myofibrillar structure, the increase in muscle loss rate and the decrease in water holding capacity.     

Antioxidant and antithrombotic effects of green mussels (Perna canaliculus) in rats

In the past decade, the use of marine mussels as seafood is being more popular. They considered being a rich source of various nutritional bioactive compounds that aroused the scientific community's interest. This study investigated the antioxidant and the antithrombotic consequences on Sprague-Dawley male rats after adding dried New Zealand mussel Perna canaliculus in their diet. The biochemical, hematological and histopathological changes were also observed. Forty rats were divided into four groups according to the amount of dried mussels in their diet, in addition to a control group that consumed a basal diet only. Group 1 consumed 25% dried mussels in its basal diet; Group 2 consumed 35% dried mussels in its basal diet, and Group 3 was consumed 45% dried mussels in its basal diet. The biochemical parameters showed improvements in liver function. Interestingly, the lipid profile decreased, especially the low-density lipoprotein cholesterol (LDL-C) levels which were reduced significantly in Group 3 (p < .01). These observations were accompanied by a decrease in iron levels significantly as the amount of dried mussels increased (p < .01). Furthermore, the noticed changes in the hematological profile prove that there is an increase in antithrombotic activity. Dried mussels had potent antioxidant effects in the liver as shown by increased lipid peroxide (p < .05), reduced glutathione (p < .05), and glutathione peroxidase (GSH-Px; p < .05). Additionally, antioxidant activity in the kidney was shown to increase through GSH-Px activity (p < .01). In conclusion, these results indicate that consuming dried mussels resulted in improved biochemical and antioxidants activities and could be used as an antithrombotic agent.     

Effect of calcium and vitamin D2 fortification on quality characteristics of dahi

Two levels (500 and 600 ppm) of calcium (calcium phosphate and calcium citrate) along with vitamin D₂ (600 IU/L) were fortified in milk for dahi preparation. pH, water‐holding capacity and syneresis of fortified dahi were not affected significantly (P > 0.05). However, acetaldehyde content decreased and setting time increased upon fortification. Microbial count significantly (P < 0.05) decreased in calcium phosphate‐fortified dahi, whereas no difference was observed in calcium citrate‐fortified dahi. Firmness and viscosity decreased in calcium phosphate‐fortified dahi, whereas it increased in calcium citrate‐fortified dahi as compared to control. All dahi samples showed good sensory acceptability.     

Iron and calcium availability from digestion of infant cereals by Caco-2 cells

An adequate mineral intake during infancy is needed for normal growth and development. This study investigated the effect of dephytinization of four infant cereals and the use of water and follow-on formula as the liquid of reconstitution on the intestinal cell uptake of iron and calcium from infant cereals using a model that combines a simulated gastrointestinal digestion adapted to the gastrointestinal conditions of infants younger than 6 months and the Caco-2 cell line. Iron and calcium uptake by Caco-2 cells from most infant cereals was significantly (p < 0.05) improved when a phytase was added. When infant cereals were reconstituted with water, dephytinization increased iron (3.2–19.5 vs. 3–10%) and calcium (0.66–2.3 vs. 0.35–0.59%) availability compared to the same infant cereals reconstituted with a follow-on formula. We can conclude that dephytinization of infant cereals and water addition improved iron and calcium availability, depending on the infant cereal used.     

Determination of textural deterioration in fish meat processed with electrospun nanofibers

Nano-applications are named as one of the novel methods, which provide many advantages like a larger contact area on the surface of fish fillets with less material. The goal of the study was to reveal the textural profile changes correlated with TPB growth of fish fillets coated with nanofibers having 2.47 ± 0.68 mV zeta potential value and 172 nm diameter. The difference of TPB count between control (CS) and the fish fillets treated with nanofibers (NG) reached 3.45 log CFU/g (p < .05) on the sixth day. The hardness value of CS was decreased (p < .05) (the decline: 68%) while the hardness of NG was found to be much more stable (the change: 42%). The highest change in springiness for CS and NG samples was determined as ~24 and ~15%, respectively, for 12 days. Cohesiveness values of CS were slightly increased, but those of the fish fillets coated with nanofibers were remarkably decreased. The coefficient of correlation analysis between TPB count and cohesiveness values was determined as “r = −.026 and r = .796” for CS and NG, respectively. Chewiness values of CS were significantly decreased (p < .05). However, chewiness values of the fish fillets coated with nanofibers were found as much more stable (p > .05). The results revealed that nanofiber coating limited the increase of TPB in fish fillets; it also better kept the textural profile of fish fillets as compared to CS stored at 4°C. The study could play a guiding role in further food nanotechnology applications in the industry and food science.     

An improved vacuum-steam pulsed blanching machine design and garlic scape blanching verified experiment

Vacuum-steam pulsed blanching (VSPB) is an emerging blanching method resulting in high efficiency and product quality. However, inconvenient loading, small loading capacity, uneven rinsing and imprecise control hinder its application in food industry. Therefore, the current work aimed to design a VSPB machine, including selection of components, building a control system and designing a steam nozzle in order to increase the load capacity and improve device control. For this purpose, a horizontal blanching chamber with internal nozzle was designed and optimized using CFD method. The vacuum chamber design required a more evenly distributed steam inlet. A water-sealing vacuum pump, a cooling device and a hardware system were developed. The distribution of steam released from the nozzle in the chamber was numerically investigated by solving the three-dimensional Reynolds-averaged Navier-Stokes equations, with a velocity uniformity index value of 0.448. The validation blanching test was conducted using garlic scape as the test material. The steam holding time and the number of cycles significantly affected (p < 0.05) the color of the garlic scapes. Peroxidase (POD) activity decreased with the increase of blanching cycles until the enzymes were completely inactivated. VSPB significantly decreased (p < 0.05) the lignin content of the garlic scapes. The findings indicate that the best results were obtained after 2 cycles of VSPB and steam holding time of 30 s.Industrial relevanceHot water and steam thermal blanching are the two most frequently used blanching methods in food processing. Generally, they are used as a pretreatment before drying, freezing or canning of different fruits and vegetables. In current work, an improved vacuum-steam pulsed blanching machine was designed and the validation blanching test with garlic scape as the material indicated that VSPB operation was effective in preventing the synthesis of lignification in garlic scapes. By considering enzyme inactivation, lignification, color, and other quality attributes, 2 cycles of VSPB and steam holding for 30 s were proposed as the optimal VSPB conditions.     

Development of antimicrobial hydrogel with edible formulations to control foodborne pathogens on food surfaces consumed raw

This study developed antimicrobial hydrogels to decrease the foodborne pathogen cell counts on raw food surfaces. Hydrogels 1 (5% sodium alginate +1% agar +0.2% calcium chloride (CaCl₂) + 40% glycerol) and 4 (1% κ-carrageenan +1% xanthan +40% glycerol), loaded with 0.5% grapefruit-seed extract or 0.5% citrus extract exhibited the highest antimicrobial activities (p < 0.05) within 1 min at 4 °C. However, hydrogel 1 was more effective than hydrogel 4 (p < 0.05) at reducing the foodborne pathogen cell counts. Hydrogel 1 reduced the Listeria monocytogenes and Escherichia coli counts (on the surface of raw beef; by 1.8–2.8 log CFU/cm²) and the Vibrio parahaemolyticus counts (on the surface of sliced raw fish; by approximately 99%) within 1 min. No substantial changes were observed in the appearance or sensory qualities of the meat during this application. Therefore, hydrogel 1 demonstrated the potential to improve the safety of raw food without altering its sensory aspects.Industrial relevance textFor raw beef and fish consumption, non-thermal decontamination technologies are necessary. Thus, antimicrobial hydrogels were developed in this study with edible components. When the antimicrobial hydrogels were attached on the meat surface, foodborne pathogens were significantly reduced within 1 min. Therefore, the antimicrobial hydrogels could be used to improve the food safety for fresh meat consumed raw.     

Influence of Oven-Drying Temperature on Physicochemical and Functional Properties of Date Fibre Concentrates

Agri-food by-products rich in dietary fibres may be used as feeds and health foods. Owing to its high fibre content, date flesh could be useful in human nutrition. It is interesting to study the influence of oven-drying temperatures of date fibre concentrates (DFC) on their physicochemical and functional properties for possible use as a potential fibre source in the enrichment of food. DFC from 11 Tunisian date cultivars were dried at different temperatures (40, 50 and 60 °C) and analysed regarding proximate composition (moisture, ash, protein and lipids), physicochemical (water activity (a _w), pH) and functional properties (water holding capacity (WHC), swelling capacity (SC), oil holding capacity (OHC) and emulsifying capacity (EC)). DFC dried at different temperatures showed interesting functional characteristics such as hydration properties, high OHC (2.73–4.60 g oil/g dry fibre) and EC (5.93–12.87%) values. Although drying temperatures promoted little modifications affecting the physicochemical properties of DFC, significant decreases in WHC, SC and EC of DFC were noticed at the highest temperature (60 °C) for most of the date varieties. The observed influence of drying temperature on functional DFC properties calls for the use of low temperature in order to obtain DFC as suitable food ingredient.     

Recovery of Native Potato Protein Comparing Expanded Bed Adsorption and Ultrafiltration

Obtaining native protein from potato fruit water (PFW) acceptable for food consumption was attempted by comparing expanded bed adsorption (EBA) and ultrafiltration (UF).The methods were assessed on their process performance and the product quality. Extractable tuber proteins were recovered from lab-prepared PFW either by adsorption to an EBA column using a mixed mode resin (0.31 L) or by batch concentration in an UF (10 kDa MWCO, 0.093 m²) unit and then freeze dried. The yields on protein and esterase activity were higher (p < 0.05 and p < 0.01; Mann–Whitney U-test) in UF (3.2 g l⁻¹ PFW and 3.17 kU l⁻¹ PFW) than in EBA (1.8 and 1.21). The performance difference was also reflected in process productivity for esterase activity which was fivefold better (p < 0.01) in UF (4.30 kU h⁻¹) than with EBA (0.84) due to the higher enzyme retention; protein productivities were the same. The content of solanidine glycoalkaloids was depleted to moderate levels but came out unaffected by the processing method: EBA 286 ppm, UF 213 ppm. The low levels of chlorogenic acid in all EBA preparations were negatively correlated to high brightness score (L* = 73.8%), a favorable attribute in food-quality proteins. Both methodologies produced native preparations of comparable protein content (75%). EBA processing, however, increased the fraction of the patatin protein which may offer advantages in food applications.     

Food safety education makes the difference: food safety perceptions, knowledge, attitudes and practices among Turkish university students

This study evaluated the influence of food safety education on the food safety perceptions, knowledge, attitudes, and practices among Turkish university students. Structured questionnaires were applied to 275 students majoring in “health or food” and 570 students majoring in “non-health or non-food” on a face-to-face basis. Food has positive connotations since associated primarily with taste and hunger in both groups. Freshness of the food product was the most important factor for the “health or food major” group, which was stated as quality for the “non-health or non-food major” group, when shopping for food (p < 0.05). Food poisoning was the main risk associated with foods in the “health or food major” group whereas fats was the most popular choice for the same question in the other group (p < 0.05). Positive influence of food safety education was clear from the results since a significant difference existed between the mean scores of knowledge, attitudes, and practices according to major discipline (p < 0.05). However, persistent food safety attitudes and practices showed little improvement with education. Although a significant difference existed between the disciplines, students in both groups did not have knowledge on the risk of raw white cheese consumption (p < 0.0001). High number of students shared their bowls with other people, consumed raw eggs and raw meat, and ate cooked foods left at room temperature more than 6 h if covered. Scientists and doctors were more trusted sources of information about serious food risks (p < 0.05). Trust in governmental agencies was significantly less in both groups.     

Ethanolic guava leaf extract with different chlorophyll removal processes: Antioxidant properties and its preventive effect on lipid oxidation in Pacific white shrimp

Sedimentation process (GLE-S) or chloroform (GLE-Ch) were used for dechlorophyllisation of ethanolic guava leaf extract (EGLE). EGLE without chlorophyll removal (GLE-C) was served as control. Among all the extracts, GLE-S had the lowest chlorophyll a, chlorophyll b, and total chlorophyll contents (P < 0.05). Extraction yield was highest in GLE-C, followed by GLE-S and GLE-Ch, respectively. Total phenolic content and antioxidant properties were highest in GLE-S (P < 0.05). When Pacific white shrimp (PWS) was pre-treated with GLE-S at varying doses (0.5% and 1%), lipid oxidation products were monitored as compared to the control (CON) and those pre-treated with 1.25% sodium metabisulphite (SMS-1.25) during refrigerated storage (4°C) for 12 days. Lower lipid oxidation was recorded for PWS pre-treated with GLE-S, especially at 1%. Therefore, sedimentation process, a green method, showed promising efficacy for producing EGLE free of green colour with improved antioxidant properties. The extract effectively reduced lipid oxidation in PWS during refrigerated storage.     

Improved gelation functionalities of myofibrillar protein from pale,soft and exudative chicken breast meat by nonenzymatic glycation with glucosamine

The potential of nonenzymatic glycation of myofibrillar proteins (MPs) to improve the gelation functionalities of pale, soft and exudative (PSE‐like) chicken breast meat was investigated. MP suspensions (4 mg mL^?1) obtained from both normal and PSE‐like chicken breast meat were mixed with glucosamine at a ratio of 1:6 (protein : glucosamine) in phosphate‐buffered saline (0.6 m KCl, 20 mm K₂HPO₄/KH₂PO₄, 0.02% NaN₃ and pH 7.5) and incubated at 37 °C for 12 h. Untreated normal and PSE‐like MP suspensions maintained at 4 °C were used as positive and negative controls, respectively. The glycation treatment increased the surface hydrophobicity but decreased the reactive sulfhydryl contents compared to those of the control (P < 0.05), indicating that the tertiary conformation of the protein changed. Correspondingly, these glycated samples also exhibited significant improvements in gel strength and the water‐holding capacity (P < 0.05). Conclusively, nonenzymatic glycation is a potential technique to improve the properties and offer a means for effective use of PSE‐like meat.     

Effect of chlorophyll removal and particle size upon the nutritional and technological properties of powdered by‐products from artichoke (Cynara scolymus,L.) industrial canning

In this study, the effect of the particle‐size fractionation (Ø < 0.212 mm and 0.212 mm < Ø < 0.991 mm) and chlorophyll extraction on the nutritional and technological properties of the powdered artichoke ingredient was evaluated. The contents of minerals, protein, fat, carbohydrates and dietary fibre together with the content in bioactive compounds such as inulin and phenolics were determined. Other properties such as water‐ and oil‐holding capacities, water activity and antioxidant capacity were measured. The ingredient with chlorophyll and the lowest particle size presented the highest phenolic content and antioxidant capacity (8.4 mg of vitamin C equivalents per 100 g of dry matter) and water‐ and oil‐holding capacities. The removal of chlorophyll increased the oil‐holding capacity (from 59.7% to 94.6%), which was much higher than in the coarse ingredient (34%), but has a deleterious effect reducing the antioxidant capacity and the inulin content. The ingredients also showed high dietary fibre (22.5–33%), inulin (9–16%) and mineral (7.5–7.8%) contents. Although the ingredient with chlorophyll and smaller particle size had the higher antioxidant capacity, the removal of chlorophyll improved the technological properties to be used as food ingredient without affecting significantly to the nutritional value.     

Preparation and functional characterisation of fish skin gelatin and comparison with commercial gelatin

Gelatin was extracted from the skin of farmed giant catfish (GC) and tilapia (TP) at a yield of 19.50% and 23.34% (wet wt). It was high in protein (84–88%) but low in fat (0.09–1.24%) and ash content (0.15–0.17%). The GC exhibited lower emulsifying activity (24–35%), but greater foam ability (98–110%), water holding capacity (477–844%) and fat binding capacity (2541–3314%) than commercial beef skin gelatin (BF) (P < 0.05). GC and TP showed comparable functional properties to BF. SDS‐PAGE patterns of TP gelatin showed high band intensity for the α‐ and β‐components, while the lowest band intensity of the major component was found in the BF. From the study, it can be concluded that the farmed freshwater fish skin GC and TP is a prospective source for producing a significant gelatin yield with desirable functionalities. Because of these, fish skin gelatin could be more effectively and widely used in food industries as a good food ingredient.     

The impact of desmin on texture and water‐holding capacity of ice‐stored grass carp (Ctenopharyngodon idella) fillet

The objective of this work was to analyse the role of desmin in texture softening and water‐holding capacity (WHC) of ice‐stored grass carp fillet. Results indicated that shear force of the fillet decreased sharply within 3 days, while drip loss increased during the whole ice storage. Water mobility and distribution were measured by low‐field ¹H NMR T₂ relaxation that revealed a positive correlation (P < 0.01) between WHC and the mobility of the immobilised water (T₂₁ relaxation time). Meanwhile, negative correlation could be established between intact desmin and drip loss (P < 0.01). Intact desmin was extremely correlated with shear force (P < 0.01) and positively correlated with calpains activity (P < 0.05). This study demonstrated that the degradation of desmin was involved in the mobility of the myofibrillar water and softening of grass carp fillet during ice storage. Furthermore, calpains autolysis seemed to result in desmin degradation.     

Improvement of tenderness and water holding capacity of spiced beef by the application of ultrasound during cooking

The aim of this study was to assess the effects of power ultrasound‐assisted (0, 400, 600, 800 and 1000 W, frequency of 20 kHz) cooking (80, 100, 120 min) on spiced beef. The results showed that power ultrasound could significantly increase the salt content (P < 0.05). For water holding capacity, the ultrasonic treatment could significantly reduce the pressure loss and free water content while improving the immobilised water content (P < 0.05). And ultrasonic treatment improved hardness compared with control (P < 0.05). However, the effects on the springiness, the chewiness and the resilience of the spiced beef were not significant (P > 0.05). As for microstructure, the myofibrils of beef were ruptured by ultrasonic treatment along with the Z‐lines leading to the muscle swelling. The results indicated that the application of ultrasound during cooking could effectively promote the penetration of salt, improve the water holding capacity and ameliorate the tenderness of spiced beef.     

Comparison of structural,antioxidant and immuno‐stimulating activities of polysaccharides from Tremella fuciformis in two different regions of China

In this study, we compared the chemical structure, antioxidant and immuno‐stimulating activities of two polysaccharides, TPS–FJ and TPS–SC, extracted from Tremella fuciformis from two of the major cultivation regions of China. TPS–FJ and TPS–SC contained protein and high uronic acid. Average molecular weights of TPS–FJ and TPS–SC were 45 461 and 25 981 kDa, respectively. A triple‐helix conformation was exhibited by TPS–FJ but not by TPS–SC. TPS–FJ and TPS–SC contained same monosaccharides but in different ratios. Both the polysaccharides displayed characteristic polysaccharide bands in their Fourier transform infrared and NMR spectra, shown high water and oil holding capacity, and retained antioxidant potential after simulated gastrointestinal digestion in vitro. TPS–FJ significantly (P < 0.05) stimulated the nitric oxide, tumour necrosis factor‐α and interleukin‐6 production of RAW 264.7 cells with higher reactions than those of TPS–SC in vitro. Thus, Tremella fuciformis polysaccharide can be used as a potential antioxidant and immunomodulatory ingredient in food industry.