Food Biophysics最新文献

Bocaiuva is the fruit of the palm tree Acrocomia aculeata (Jacq.) Lodd, native to various regions of Brazil, particularly in the Cerrado and Pantanal biomes. However, its commercialization is hindered by its fibrous nature and short shelf life, leading to post-harvest losses. This study aimed to obtain bocaiuva slices at different infrared drying (IRD) temperatures (60, 70 and 80 ºC). It was found that a shortening in the drying time at 80 ºC caused an increase in the drying rate. Fick’s second law and Page’s equation were suitable for describing the process behavior. The thermodynamics and energetic analysis demonstrated higher energy efficiency at 80 ºC. Lower temperature (60 ºC) promoted lower total color difference and hygroscopicity, and higher volumetric shrinkage. The results suggested that IRD at 80 ºC was able to produce bocaiuva slices with suitable physical characteristics. Furthermore, the production of dried bocaiuva contributes to the regional development of the Cerrado biome, thereby enhancing the bioeconomy.

Washing is a key process in surimi processing, whereby lipids, water-soluble proteins, pigments, and other factors that impede gel formation are separated from the fish. However, this process significantly reduces the meat yield of raw fish and destroys its nutrients, generating more organic wastewater. To enhance the process efficiency, ultrasound is used to assist washing process. This study aims to investigate the effects of ultrasound-assisted washing at different power levels (0 W, 150 W, 250 W, 350 W, and 450 W) on the quality, biochemical characteristics, protein conformation and gel-forming ability of surimi from silver carp. The results showed that ultrasound-assisted washing could increase yield by over 4% and reduce crude fat content by approximately 0.5% than control group. Protein secondary structure indicated that ultrasonic treatment of 250 W didn’t cause significant loss of α-helix. Moreover, the gel strength of 450 W group was roughly 17% more than that in control group. 250 W ultrasound-assisted washing was the most effective and significantly improved the productivity and quality of surimi.

A conformational difference in gum arabic (GA) in aqueous and emulsion systems can influence its interaction with guar gum (GG). Therefore, in this study, the rheological and tribological properties of GG mixed with an orange oil emulsion containing GA at varying concentrations were investigated and compared with those of GG-GA mixtures. As the GA concentration was increased, the apparent viscosity of GG mixtures with either GA or GA-based emulsion (GAE) tended to decrease. Specifically, with a higher GA concentration (> 1.5%), the GG-GA mixtures showed a lower relative apparent viscosity than the GG-GAE mixtures. In contrast, except for GG-GA mixture with 6.0% GA, all other mixtures showed lower tan δ values (0.66–0.69) than GG alone (0.72), indicating an enhancement of weak gel-like properties. At a lower GA concentration (< 3.0%), GG-GA interactions in the aqueous system produced a lower relative tan δ value than those in the emulsion system, whereas the opposite result was observed with a higher GA concentration (> 4.5%). In addition, each type of mixture exhibited different tribological properties. As the GA concentration was increased, the friction coefficient (μ) values of both tended to decrease. Especially, the GG-GAE mixtures attained lower μ values than the GG-GA mixtures, thereby indicating that the former have better lubricant properties. These results demonstrated that the conformational change in GA while emulsifying oil droplets influences its interactions with GG.

In this study, the influence on the dough sheet’s overall quality induced by phosphate salts and hydrocolloids was evaluated. To clarify the internal structure of wheat dough, thermomechanical and rheological properties were performed on the dough, whereas the texture and cooking properties were evaluated on dough sheets. Results from the mixolab analysis showed a linear relationship between the content of hydrocolloids and phosphate salts (ranging from 0.1–0.7%) and key parameters, including gluten strength (C2), starch gelatinization (C3), and dough stability. These results were consistent with rheological measurement for storage G’ and loss G” moduli. The power-law model indicated that the dough possessed stronger and slower relaxation properties. The addition of sodium pyrophosphate and xanthan notably enhanced the hardness, springiness, and chewiness of texture properties. Microstructural analysis revealed that the internal molecules of dough sheets exhibited tighter interaction, resulting in low porosity and continuous network. Our study highlights the essential role of phosphate salts and hydrocolloids in improving the quality of wheat products. Additionally, we gained a deeper understanding of the change in the internal structure of dough sheets during the boiling process.

Ergosterol possesses a variety of physiological activities, however, its application is limited due to its poor water solubility and photosensitivity. In this study, by using the ultrasonic-assisted heating method, recombinant human H-ferritin (rHuHF)–ergosterol nanocomposites (FEs) were designed, and after the characterization, the light stability, serum stability, sustained release character, and cholesterol-lowering property in vitro were analyzed. The results showed that FEs maintained a spherical morphology with the same particle size as rHuHF. About 17 ergosterol molecules were successfully encapsulated in one ferritin molecule with an encapsulation rate of (27.28 ± 0.29)% and a drug loading of (1.63 ± 0.02)%. The light stability of FEs was increased compared with free ergosterol molecules. The FEs also exhibited good serum stability. The results of simulated gastrointestinal digestion indicated that the rHuHF cage was able to prolong the release of ergosterols. FEs digesta can reduce the solubility of cholesterol in micelles. Additionally, molecular docking displayed that ergosterol can competitively inhibit cholesterol binding to human Niemann-Pick C1-Like 1 (NPC1L1), which might play an important role in preventing the delivery of cholesterol to the membrane for accumulation. This work offers an approach to encapsulate and deliver ergosterol depending on the advantage of ferritin nanocage, which has the potential to be applied in food industry.

Zingiber cassumunar Roxb. rhizome extract has high potential as an antimicrobial agent, which can be applied in various food production processes and plays role in inhibiting various foodborne pathogenic microorganisms. The purpose of this research was to study the mechanism and stability of the extract’s antimicrobial activity, especially when observed from the degradation of microbial cells. Specimens were extracted by maceration method with three types of solvents with different polarities and steam distillation. The 25% extract using ethyl acetate solvent showed antimicrobial activity against Gram-negative bacteria (Enterobacter spp. and Pseudomonas spp.); Gram-positive bacteria (Listeria monocytogenes); and fungi (Rhizopus oryzae and Penicillium spp.) in well-diffusion assays. The antimicrobial activity of the extract was lower than several commercially used antibiotics such as antibacterial (penicillin G and streptomycin) and antifungal (nystatin) but exhibited broad inhibition spectrum against pathogen samples. The antimicrobial activity of the extract will increase at a low pH condition (pH 4–5) and is stable in 1–4% salt solution. Although the inhibitory activity was decreased slightly upon heating, the antimicrobial activity was stable up to 15 min of exposure to high temperatures (80^○C and 100^○C). Antimicrobial activity of the extract was reported to be higher in a spheroplast and protoplast condition. Leakage of metal ions such as calcium and potassium ions indicated that the activity of the extract could interfere with cell permeability so that the cells become lysed. The extract caused some damage to the bacteria and fungi cell bodies such as holes, curls, shrinkage, elongation, and swelling.

Graphical Abstract

The interaction between a low molecular weight (i.e., 19 kDa) ethyl cellulose (EC) and a commercial monoglyceride (MGc) in the development of EC-MGc oleogels was evaluated through rheological, DSC, and infrared spectroscopy measurements. The oleogels were developed through cooling (80°C to 2°C, 10°C/min) vegetal oil solutions of EC at concentrations above (10%), below (7%), and at EC’s minimal gelling concentration (8%), and in EC-MGc mixtures using MGc below its minimal gelling concentration (0%, 0.1%, 0.25%, 0.5%, 1%). At 0.10% MGc most of the monoglycerides developed hydrogen bonds with the EC developing oleogels structured through EC-monoglyceride-EC interactions. As the EC concentration increased the EC-0.1% MGc oleogels achieved higher elasticity (G’) than the EC oleogels. Using MGc concentrations ≥ 0.25% the excess of monoglyceride increased the oil’s relative polarity favoring the EC-EC over the EC-monoglyceride-EC interactions. Below 10 °C the monoglycerides in the oil crystallized within the free spaces of the entangled EC fibers acting as active filler. Thus, at the same EC concentration the EC-0.25% MGc, EC-0.50% MGc, and EC-1% MGc oleogels achieved higher G’ than the corresponding EC-0.10% MGc oleogels (P < 0.01). This behavior was more evident as the EC concentration increased. The rheological measurements during cooling showed that below 40 °C the EC went through a structural rearrangement that decreased the oleogels’ elasticity. Since the structural rearrangement was cooling rate, EC and MGc concentration dependent, these factors could be used to tailor the rheological properties of oleogels developed with low molecular weight EC.

Tea egg is a Chinese traditional snack and leisure food, fresh chicken eggs and tea are the main ingredients. The influence of tea is the most important one, because the polyphenols in different teas can affect the egg white gel (EGL) and will impact the quality and flavour of tea eggs. To investigate the effects of tea on the physicochemical characteristics of EGL during tea egg making, the common used tea (green and black tea), and their usual physical form (in leaf and powder) were selected, respectively. The results indicated that the physicochemical characteristics of EGL were more susceptible to green tea than black tea. EGL also had different results on the physical form of tea. When the tea concentration ranged from 1 to 12 g/100 mL (per gram dry tea in 100 mL of water), the soluble protein content and surface hydrophobicity in the EGL were both direct proportional to the tea concentration, whereas the pH exhibited an inverse relationship. The water holding capacity in green tea groups was like an inverted “U”, but it was kept increased in black tea groups. The content of free sulfhydryl groups in tea leaf groups was like an asymmetric inverted “V”, but it was positive correlation with the amount of tea in powder groups. Considering only the physicochemical properties of protein gel in egg white, green tea in leaf form of 6 g/100mL could make eggs with the best gel quality and stronger tea flavour. This study will standardize tea eggs making, and promote the sharing of traditional Chinese cuisine with the global community.

Pectin was isolated from the African star apple (ASA) (Chrysophyllum albidum) fruit at a fully ripe stage from two geographical zones in Ghana. The study employed Box-Behnken design to determine the effects of extraction conditions, time (30–90 min), temperature (70-90^oC), and pH (2.5–3.5) on yield, degree of esterification and uronic acid content of the pectin extracts. The optimal conditions of the design (90^oC for 60 min at a pH of 2.5) predicted a yield of ~ 11%, with a degree of esterification of 65% and uronic acid content of 75%, which were similar to the experimental values of yield (8.5–10.6%), degree of esterification (DE) (66.8–67.1%) and uronic acid (UA) content (74.5–76.2%). The ASA pectin extracted were characterized in comparison with commercial citrus pectin based on their physicochemical properties. The emulsification capacity of the pectin revealed higher emulsion stability, closely related to commercial citrus pectin. FT-IR analysis of the pectin revealed the presence of a polygalacturonic acid in both samples. The study confirmed that commercial citrus pectin and the citric acid extracted pectin from ASA had comparable characteristics and could be utilized as an alternative extraction source.

Aflatoxins (AFs) are toxic secondary metabolites of filamentous fungi which can reduce the quality of several food commodities like hazelnut and hazelnut products. For the AFs, the data were fitted to polynomial response models using multiple regression analysis, resulting in high coefficients of determination (R² values ranging from 0.8917 to 0.9674) for each type of aflatoxins. The optimal conditions for achieving maximum degradation percentages for total aflatoxins (AFT) and AFB1 were determined to be US power of 80W, enzyme treatment of 2.5 U g sample, and 20 min of US application for 12.5 µg kg AFT conditions after graphical and numerical optimizations. The optimum conditions resulted in 44.33% and 45.58% degradation for AFT% and AFB1 respectively, with predicted values of 43.93% and 44.17% for AFT% and AFB1. The data exhibited that, enzyme treatments were not significant for degradation for AFB1% and AFT%, whereas significant for AFB2 and AFG2. Depending on the initial AFT concentration, more than 50% degradation rate was achieved by current design parameters. Study results indicated that US treatment can alter certain quality parameters of hazelnut paste, including changes in aroma, a decrease in browning index, and a slight increase in peroxide value.