Food Science and Technology International最新文献

Chitosan nanocapsules containing polyunsaturated fatty acid (PUFA) concentrates from tuna oil, with EPA + DHA contents around 57% (w/w), were developed by emulsification process, using different chitosan concentration (1.0%, 1.5%, 2.0%, w/v) and stirring speed (10,000, 15,000, 20,000 rpm). The effects of these parameters on particle size and zeta potential were evaluated. The physical and oxidative stabilities were used to measure the product quality during storage. Chitosan concentration, stirring speed and its interaction significantly affected (p < 0.05) the particle size. In addition, chitosan concentration significantly affected (p < 0.05) the zeta potential of nanocapsules emulsion. Based on the results of physical and oxidative stabilities, the nanocapsules were stable for 30 days under refrigeration temperature (7 °C), and with 1.5-2% chitosan resulted in improved protection against oil oxidation. The nanocapsules produced with 2% chitosan and 10,000 rpm showed the lowest variations of polydispersity index and nanocapsules size after 30 days of storage (221.8 ± 3.0 nm). These conditions can be considered the most suitable to produce nanocapsules of PUFA concentrates from tuna oil using chitosan as wall material. These nanocapsules showed physical characteristics and oxidative stability, which could enable their application in the food industry, representing an important source of EPA and DHA fatty acids.

Microbial biofilm formation represents a serious problem for both food industry and households. Natural biofilms are formed mostly by multiple species, and show resistance against most of the usual sanitizers. In this study, the effects of cinnamon (Cinnamomum zeylanicum), marjoram (Origanum majorana) and thyme (Thymus vulgaris) essential oils (EOs) and their main components (cinnamaldehyde, terpinene-4-ol, and thymol) were investigated on four-species biofilms of Escherichia coli, Listeria monocytogenes, Pseudomonas putida and Staphylococcus aureus. Minimum bactericide concentration (MBC) and killing time were determined by means of the microdilution method. MBC of the investigated EOs and components was between 0.5 mg/mL (cinnamaldehyde) to 25 mg/mL (terpinene-4-ol). Killing times for the four-species suspension were 5 or 10 min, time spans usable in the food industry. For eradication of the mixed-population biofilm from stainless steel (SS), polypropylene (PP), tile and wood surfaces, EO- or EO component-based disinfectant solutions were developed, and their effects were compared to a peracetic acid-based industrial sanitizer (HC-DPE). Total eradication of biofilms (99.9%) was achieved, with solutions containing cinnamon and thyme EO and EO components, from SS and PP, but not from tile or wood surfaces. Apparently, cinnamon EO, terpinene-4-ol and thymol have better disinfectant activity than HC-DPE.

This research was performed to investigate the effect of hazelnut cake (HC) as a cold press waste product on the physicochemical and textural properties of the frankfurter-type sausages during cold storage. According to the highest emulsion capacity (174.14 mL oil/g), emulsion stability (79.86%), and optimum rheological results obtained in emulsions, 1% HC concentration was selected for the utilization in the sausage formulation. HC added sausage was compared with the control sample at 4 °C for 60 days of storage. HC addition increased the hardness and chewiness properties and decreased weight loss of sausages during storage. The incorporation of HC in formulation slowed down the increase in malondialdehyde and conjugated dienes concentrations after the 15th day of storage compared to the control sausages. The results demonstrated that HC presented a good opportunity for protecting the quality parameters of emulsified meat products during storage.

This work aimed to explore the potential use of Rhodomyrtus tomentosa ethanol leaf extract (RTEL) as an alternative food preservative agent for controlling the growth of Staphylococcus aureus. Antibacterial activities against food-isolated S. aureus were performed using disc diffusion and broth microdilution assays, followed by evaluating in vivo subacute oral toxicity of the extract. Salad dressing was used as a food model to study bactericidal properties and consumer acceptability. RTEL remarkably inhibited S. aureus with minimum inhibitory concentrations (MICs) ranging from 7.81-62.5 µg/mL. Repeated oral doses (5, 50, and 300 mg/kg RTEL) for 28 days did not affect any of the measured toxicity parameters. The no-observed-adverse-effect-level (NOAEL) of RTEL was noted as more than 300 mg/kg body weight/day. The utilization of RTEL (12.5 mg/mL) in the vinaigrette salad dressing did not affect the consumer acceptability of the product, remarkably killed the pathogen within 3-9 h of exposure. The results indicated that RTEL is safe and effective as a natural anti-staphylococcal controlling agent that could be utilized in food systems. Further work is required on the effects of enterotoxin production, an important virulence factor of S. aureus responsible for food-borne disease.

The germinated clove basil (Ocimum gratissimum) and sweet basil (Ocimum basilicum) seeds being a potent source of dietary fibre, minerals and antioxidants are utilized as functional ingredients for the enrichment of gluten-free pasta. The germinated clove basil seed and sweet basil seed incorporated pastas with acceptable sensory scores were developed by substituting 30% and 15% of gluten-free flour respectively. Basil seed pastas exhibited lesser cooking time (7-8 min), cooking loss (6%) and similar texture as that of control. The clove basil seed pasta exhibited better cooking quality, nutritional and antioxidant properties than the sweet basil seed pasta due to higher level of basil seed flour substitution. Consumption of one serving of clove basil seed pasta (75 g) could meet the dietary fibre (49%, 58%), protein (15%, 17%), magnesium (18%, 21%), phosphorus (22%, 22%), manganese (28%, 28%) and copper (28%, 28%) daily requirements of sedentary adult men and women, respectively.

Tender coconut water (TCW) is a natural drink rich in natural electrolytes, minerals, salts and sugars; it has good health benefits. But, its shelf-life is very limited because of the active nature of enzymes present in it when exposed to air. Therefore, the processing of TCW is necessary to inactivate the enzymes. So, this study aims to observe the effect of various process parameters of pulsed electric field (PEF) on the quality parameters of TCW. For the treatment of TCW with PEF, a full-factorial design of experiments was followed with process parameters such as three levels of electric field intensity (8, 12, and 16 kV/cm), two levels of pulse width (PW) (50 and 70 μs), and six levels of the number of pulses (2000 to 12,000 pulses) were considered at a constant pulse OFF time of 75 ms. PEF treatment did not significantly change pH, total soluble solids, and viscosity. However, it significantly affected vitamin C, colour, and total and reducing sugars. PEF treatment significantly enhanced the total phenolic content and antioxidant activity by 23.17% and 42.49%, respectively. At the same time, significant inactivation of polyphenol oxidase (100%) and peroxidase (60.2%) was observed at PEF treatment conditions of 16 kV/cm, 70 μs PW, and 12,000 pulses. Moreover, no significant change in the sensory acceptability of PEF-treated TCW (16 kV/cm, 70 μs PW, 12,000 pulses) when compared to the untreated/fresh TCW, which is a promising sign.

This study was conducted to determine the variation in the chemical composition of flours derived from Locusta migratoria at two distinct developmental stages: the fourth instar and adult stages. Adult locust flour exhibited approximately two times higher fat content, similar protein content, ash content, CHNS elemental composition, and 45.7% lower total phenolic content compared to fourth instar locust flour. The flour from the adult locust was lighter, more red, and yellow than the fourth instar locust flour. Nineteen fatty acids were detected in both flours, with oleic acid, palmitic acid, and linoleic acid being the major ones. The ΣPUFA/ΣSFA of fourth instar and adult locusts was 0.82 and 0.78, respectively. The ratio of ω-6/ω-3 fatty acids was 2.1 for the fourth instar locust flour and 1.7 for the adult locust flour. Apart from gamma-aminobutyric acid (GABA), similar amino acids were found in both the flours. However, significant differences were detected in the levels of some of these amino acids between the fourth instar and adult locust flours. Of particular interest, adult locust flour showcased a GABA content of 25.4 mg/100 g dry weight, making it a valuable alternative protein source in developing innovative and nutritious food products.

Chemical oxidizers and redox enzymes have traditionally been used to enhance the quality of baked goods. However, consumers now seek natural and clean-label ingredients, avoiding those with chemical-sounding names. Honey, a natural source of glucose oxidase (GOX), represents a promising alternative to purified enzymes for baking purposes. This study aimed to evaluate the effect of honey on the molecular structure and microstructure of gluten proteins in sourdough fermented by different lactic acid bacteria (LAB) strains. Four wheat-rye (1:1) sourdoughs were prepared, each supplemented with honey and inoculated with a different LAB strain. Additionally, two uninoculated doughs, one with honey (honey dough) and the other without (control dough), were prepared under identical conditions. Electronic paramagnetic resonance spectroscopy revealed the presence of hydrogen peroxide in honey solutions, indicating its role as an active source of GOX. Raman spectroscopy showed that honey addition altered the molecular structure of gluten by increasing the proportion of random coils at the expense of α-helix structures. This change is likely attributed to the competition between honey sugars and gluten proteins for water molecules in this system. Moreover, honey led to a decrease in the free sulfhydryl content of gluten compared to the control dough, suggesting an increase in disulfide crosslinking points. These enhanced protein-protein interactions were observed in scanning electron microscopy micrographs as a coarse gluten network composed of interconnected strands and fibrils. All LAB strains exhibited optimal acidification (pH < 4.3) in honey-supplemented sourdoughs, promoting the hydrolysis of gluten proteins into smaller fragments. Overall, honey-supplemented sourdoughs showed a gradual increase in the β-sheet content while decreasing the proportion of random coils over time. This trend suggests that the polypeptide fragments interacted through interchain hydrogen bonds, leading to a more ordered structure, which likely contributes to providing dough with good baking aptitude.

Ethiopian honey wine, Tej, is the most popular traditionally fermented alcoholic beverage in Ethiopia. Owing to the spontaneous fermentation process, the final product is neither predictable nor consistent in quality. Attempts have not been made before to solve this problem. Thus, the aim of this study was to develop a potential mixed starter culture of yeast and lactic acid bacteria isolated from Tej samples for the production of Tej with consistent quality. One hundred seventy-seven lactic acid bacteria and 194 yeasts were isolated from 30 Tej samples collected from southwest Ethiopia. After sequentially testing the isolates towards physiological stress tolerance and desired metabolic products, 10 lactic acid bacteria and 10 yeast isolates were screened. Later, four lactic acid bacteria and four yeast isolates were found to be compatible in co-culture tests. Finally, the combination of lactic acid bacteria and yeast isolates was formulated using the design of expert version 7.0.0 software, and six formulates (F #1-6) were designed. Controlled Tej fermentation was performed under laboratory conditions using six lactic acid bacteria-yeast starter culture formulations. The sensory attributes, in terms of color, flavor, odor, turbidity, and overall acceptance analysis scored 4.8/5.0 (F #2) and 4.7/5.0 (F #6), with mean significant variations (p < 0.05) among the other formulates. These two formulates were considered the best-mixed starter cultures compared to the control and other formulates. Matrix-assisted laser desorption ionization-time of flight analysis revealed that the lactic acid bacteria starters (AAUL7 and AAUL10) belonged to Lactobacillus paracasei. While the yeast starters (AAUY2 and AAUY8) belonged to Saccharomyces cerevisiae. These mixed lactic acid bacteria-yeast starter cultures could be used as the best starter culture for the fermentation of Ethiopian honey wine, Tej, with consistent quality.