Removal of proteins and lipids affects structure, in vitro digestion and physicochemical properties of rice flour modified by heat-moisture treatment.

BACKGROUND: The objective of this experiment was to investigate the role of endogenous proteins and lipids in the structural and physicochemical properties of starch in heat-moisture treatment (HMT) rice flour and to reveal their effect on starch digestibility under heat. RESULTS: The findings indicate that, in the absence of endogenous proteins and lipids acting as a physical barrier, especially proteins, the interaction between rice flour and endogenous proteins and lipids diminished. This reduction led to fewer starch-protein inclusion complexes and starch-lipid complexes, altering the granule aggregation structure of rice flour. It resulted in a decrease in particle size, an increase in agglomeration between starch granules, and more surface cracking on rice granules. Under HMT conditions with a moisture content of 30%, slight gelatinization of the starch granules occurred, contributing to an increased starch hydrolysis rate. In addition, the elevated thermal energy effect of HMT enhanced interactions between starch molecular chains. These resulted in a decrease in crystallinity, short-range ordering, and the content of double-helix structure within starch granules. These structural transformations led to higher pasting temperatures, improved hot and cold paste stability, and a decrease in peak viscosity, breakdown, setback, and enthalpy of pasting of the starch granules. CONCLUSION: The combined analysis of microstructure, physicochemical properties, and in vitro digestion characteristics has enabled us to further enhance our understanding of the interaction mechanisms between endogenous proteins, lipids, and starches during HMT. © 2024 Society of Chemical Industry.

Rapid Screening of Phenolic Compounds with Anti-Enteritis Activity from Camellia oleifera Oil Using a Smurf Drosophila Model and Molecular Docking Methods.

Screening and identifying the active compounds in foods are important for the development and utilization of functional foods. In this study, the anti-enteritis activity of ethanol extract from Camellia oleifera oil (PECS) was quickly evaluated using a Smurf Drosophila model and the metabolomics approach, combined with molecular docking techniques, were performed to rapidly screen and identify compounds with potential anti-enteritis activity in PECS. PECS showed good anti-enteritis activity and inhibited the activity of 5-lipoxygenase (LOX), cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS). In particular, wighteone and p-octopamine were newly identified in C. oleifera oil and were proven to have good anti-enteritis activity. The inhibitory activity of kaempferitrin (IC50 = 0.365 mmol L-1) was higher than that of wighteone (IC50 = 0.424 mmol L-1) and p-octopamine (IC50 = 0.402 mmol L-1). Of note, the IC50 value of salazosulfapyridine was 0.810 mmol L-1. Inhibition of LOX activity is likely one of the anti-enteritis mechanisms of PECS. These new findings lay the foundation for further investigations into the underlying mechanisms of anti-enteritis activity in C. oleifera oil.

[Study on Subcritical Fluid Extraction of Essential Oil from Cinnamomum camphora and Its Antibacterial Activity].

Objective: To determine the optimum extract condition of essential oil from dry Cinnamomum camphora leaves and to study its antibacterial activity. Methods: The essential oil was extracted by subcritical fluid, and analyzed by response surface methodology based on single factor test. The chemical compositions of essential oil were analyzed by GC-MS, and the components were quantitatively determined by normalization method. The agar disc diffusion and dilution broth method were used to determine antibacterial activity. Results: The extraction rate was highest as 3. 54%,which matched with the predictive yield of 3. 56%,and the extraction time was30 min, the extraction temperature was 40 ℃,and resolution temperature was 65 ℃. 47 chemical constituents were identified and isolated from Cinnamomum camphora, which was analyzed by GC-MS. The main chemical constituents were eucalyptol( 24. 74%),bicyclo[3. 1. 0]hexan-4-methylene-1-( 1-methylethyl) ( 7. 05%),linalool( 5. 82%),caryophyllene ( 4. 75%). The essential oil from Cinnamomum camphora had different degrees of inhibition on Escherichia coli,Staphylococcus aureus, Pseudomonas aeruginosa,Bacillus subtilis. Conclusion: Subcritical fluid is suitable for the extraction of essential oil from Cinnamomum camphora and the essential oil has a good antimicrobial activity.

Comparison of structural and in vitro digestive properties of autoclave-microwave treated maize starch under different retrogradation temperature conditions.

Retrogradation is a critical step in the physical production of resistant starch. This study aimed to examine the effects of isothermal and temperature-cycled retrogradation on the structural, physicochemical properties, and digestibility of resistant starch type-III (RS3) under various thermal conditions. To create RS3, normal maize starch (NM) and Hylon VII (HAM) were treated by autoclave-microwave and then retrograded at isothermal (4 °C) or various temperature conditions (4/10 °C, 4/20 °C, 4/30 °C, 4/40 °C, and 4/50 °C). We found that temperature-cycled retrogradation possessed greater potential than isothermal retrogradation for producing short-range ordering and crystalline structures of RS3. Also, retrograded starch prepared via temperature cycling exhibited higher double helix content, lower amorphous content, reduced swelling power, and less amylose leaching in water. Furthermore, the starch digestibility was affected by structural alterations, which were more significant in HAM-retrograded starch. While, HAM-4-40 (39.27 %) displayed the highest level of resistant starch (RS).

Associations of combined phenotypic aging and genetic risk with incident cancer: A prospective cohort study.

Background: Age is the most important risk factor for cancer, but aging rates are heterogeneous across individuals. We explored a new measure of aging-Phenotypic Age (PhenoAge)-in the risk prediction of site-specific and overall cancer. Methods: Using Cox regression models, we examined the association of Phenotypic Age Acceleration (PhenoAgeAccel) with cancer incidence by genetic risk group among 374,463 participants from the UK Biobank. We generated PhenoAge using chronological age and nine biomarkers, PhenoAgeAccel after subtracting the effect of chronological age by regression residual, and an incidence-weighted overall cancer polygenic risk score (CPRS) based on 20 cancer site-specific polygenic risk scores (PRSs). Results: Compared with biologically younger participants, those older had a significantly higher risk of overall cancer, with hazard ratios (HRs) of 1.22 (95% confidence interval, 1.18-1.27) in men, and 1.26 (1.22-1.31) in women, respectively. A joint effect of genetic risk and PhenoAgeAccel was observed on overall cancer risk, with HRs of 2.29 (2.10-2.51) for men and 1.94 (1.78-2.11) for women with high genetic risk and older PhenoAge compared with those with low genetic risk and younger PhenoAge. PhenoAgeAccel was negatively associated with the number of healthy lifestyle factors (Beta = -1.01 in men, p<0.001; Beta = -0.98 in women, p<0.001). Conclusions: Within and across genetic risk groups, older PhenoAge was consistently related to an increased risk of incident cancer with adjustment for chronological age and the aging process could be retarded by adherence to a healthy lifestyle. Funding: This work was supported by the National Natural Science Foundation of China (82230110, 82125033, 82388102 to GJ; 82273714 to MZ); and the Excellent Youth Foundation of Jiangsu Province (BK20220100 to MZ).

Age is a major risk factor for cancer. Other factors, such as lifestyle or environmental exposures, may increase or mitigate cancer risks. Biological age, which considers accelerated aging processes, may, however, better predict cancer risk than chronological age. Some scientists propose using biological aging measures as an alternative for assessing cancer and other age-related disease risks, as these markers may provide a more accurate assessment of the various factors contributing to cancer risk. PhenoAge, a measure of biological aging processes in the body, could provide an alternative way to assessing aging-related cancer risks. This tool utilizes an individual's chronological age and nine biomarkers of aging processes. It has the potential to identify individuals whose aging process is accelerated compared to their peers, potentially indicating an increased cancer risk. This information may empower them to make lifestyle changes that could significantly reduce their risk. To assess the suitability of PhenoAge, Bian, Ma et al. used nine clinical chemistry biomarkers and chronological age to calculate PhenoAge in 374,463 participants from the UK Biobank. Their findings revealed that people with older PhenoAges ­ regardless of their genetic risk profiles ­ have an increased risk of cancer. Individuals with higher PhenoAge scores, indicating accelerated biological aging, had a roughly 25 percent higher risk of developing cancer. Individuals with both a high genetic risk and higher PhenoAge score had roughly double the risk of cancer. People with lower PhenoAges were more likely to have healthier lifestyles. These results suggest that adopting healthier lifestyles may slow the aging process and reduce cancer risk. While the analyses conducted by Bian, Ma et al. provide promising insights, they also underscore the need for further research. PhenoAge may offer a way to assess biological aging and identify individuals at higher risk of cancer. Those with higher PhenoAge scores may benefit from earlier cancer screening, and adopting a healthier lifestyle could potentially slow down the aging process and reduce their cancer risk. However, more studies in more diverse cohorts of people are needed to confirm that PhenoAge is a reliable marker for cancer risk and to test interventions to slow aging and reduce cancer risks in individuals with accelerated aging.

Study on the taste active compounds in Douchi using metabolomics method.

Douchi is a traditional famous seasoning in China. This study adopted electronic tongue and metabolomics to analyze the taste characteristics and taste active compounds of 12 samples from three most famous types of Douchi (Liuyang Douchi, Yangjiang Douchi, Yongchuan Douchi). Thirty-six differential metabolites mainly enriched from the arginine biosynthesis were identified among these Douchis. Umami and bitterness are considered as two taste that bring positive and negative perceptions for Douchi. The succinic acid was found to be responsible for the umami in LY, YJ and YC Douchi, with the TAVs of 2054, 643, 174, respectively, rather than the glutamic acid and aspartic acid. The leucine was identified as the main metabolite for bitterness, with the TAVs of 9, 9, 7 respectively. KEGG enrichment analysis found that the umami, sourness and saltiness might be related to alanine, aspartate and glutamate metabolism and the bitterness might be related to aminoacyl-tRNA biosynthesis pathway.

Effect of pH-Shifting Process on the Cathepsin Activity, Muddy Off-Odor Compounds' Content and Gelling Properties of Isolated Protein from Silver Carp.

Silver carp (Hypophthalmichthys molitrix) is a potential source for making surimi products. However, it has the disadvantages of bony structures, high level of cathepsines and muddy off-odor which is mainly caused by geosmin (GEO) and 2-methylisoborneol (MIB). These disadvantages make the conventional water washing process of surimi inefficient (low protein recovery rate, and high residual muddy off-odor). Thus, the effect of the pH-shifting process (acid-isolating process and alkali-isolating process) on the cathepsins activity, GEO content, MIB content, and gelling properties of the isolated proteins (IPs) was investigated, comparing it with surimi obtained through the conventional cold water washing process (WM). The alkali-isolating process greatly boosted the protein recovery rate from 28.8% to 40.9% (p < 0.05). In addition, it removed 84% GEO and 90% MIB. The acid-isolating process removed about 77% GEO and 83% MIB. The acid-isolated protein (AC) displayed the lowest elastic modulus (G'), the highest TCA-peptide content (90.89 ± 4.65 mg/g) and the highest cathepsin L activity (65.43 ± 4.91 U/g). The AC modori (60 °C for 30 min) gel also demonstrated the lowest breaking force (226.2 ± 19.5 g) and breaking deformation (8.3 ± 0.4 mm), indicating that proteolysis caused by the cathepsin deteriorated the gel quality of AC. The setting (40 °C for 30 min) considerably increased the breaking force (386.4 ± 15.7 g) and breaking deformation (11.6 ± 0.2 mm) of the gel made from the alkali-isolated protein (AK) (p < 0.05). In AC and AK gel, a clearly visible cross-linking protein band with a molecular weight greater than MHC was seen, demonstrating the presence of endogenous trans-glutaminase (TGase) activity, that improved the gel quality of AK. In conclusion, the alkali-isolating process was an effective alternative method for making water-washed surimi from silver carp.

Identification of novel α-glucosidase and ACE inhibitory peptides from Douchi using peptidomics approach and molecular docking.

In this study, the effect of Douchi extract (DWE) on α-glucosidase and angiotensin-converting enzymes (ACE) were investigated, and several novel peptides with inhibitory activity against α-glucosidase and ACE were identified using peptidomics approach based on UPLC-MS/MS. The average inhibition rates of DWE on α-glucosidase and ACE were 73.75-78.10% and 4.56-27.07%, respectively. In the DWE, a total of 710 peptides were detected. Two novel peptides with potential inhibitory activity against α-glucosidase were identified using the correlation analysis, database alignment and molecular docking methods. They were DVFRAIPSEVL and DRPSINGLAGAN, with the IC50 values of 0.121 and 0.128 mg/mL, respectively. Also, four novel peptides with potential inhibitory activity against ACE were identified: PSSPFTDLWD, EEQDERQFPF, PVPVPVQQAFPF and PSSPFTDL, with IC50 values of 1.388, 0.041, 0.761 and 0.097 mg/mL, respectively. These results indicated that combining peptidomics and molecular docking is an effective alternative strategy for rapidly screening numbers of novel bioactive peptides from foods.

The effect of heat-moisture treatment changed the binding of starch, protein and lipid in rice flour to affect its hierarchical structure and physicochemical properties.

This study investigated the effect of removing proteins, lipids and starch on the structure, physicochemical properties and digestion properties of rice flour (with 30% moisture) treated with heat moisture treatment (HMT). According to the results, HMT caused the adhesion and agglomeration of the rice flour, promoted the binding between starch, protein and lipid molecular chains and led to the formation of complexes (especially starch-lipid complexes), which hindered the removal of non-starch components. Compared to the untreated rice flour, the HMT treated lipid-removal rice flour had small changes in their crystallinity, gelatinization temperature and viscosity property. After removing protein, the crystallinity, peak viscosity, final viscosity, breakdown and starch digestibility were sharply increased. In particular, the peak viscosity increased from 811 cP to 1746 cP and the enthalpy change increased from 5.33 J/g to 10.18 J/g. These findings are helpful in understanding the contribution of removing endogenous proteins and lipids to the physicochemical changes of HMT treated rice flour during its heating process and thus can be helpful in controlling the quality of rice flour through HMT.

[Study on rapid non-destructive detection of the freshness of paddy based on NIRS].

A prediction model of paddy storage time was established based on near infrared reflectance (NIRS) and chemometrics. A spectroradiometer was used for collecting spectra in the wavelength range from 950 to 1 650 nm. The NIR spectra were collected from 90 samples of paddy. The best pretreatment method was obtained while choosing the total spectra area combined with PLS using the UNSCRAMBLER 9.7. The best pretreatment method is first derivative combined with S. Golay, and the number of principal components is 7. The model is feasible, because the r2 is 0.9679, RMSEP is 54.51 and the result of T-test is passable while validation method is cross validation In this paper, a feasible method is established to measure the storage time of paddy based on near infrared reflectance(NIRS)and chemometrics.

Effect of Staphylococcus aureus Contamination on the Microbial Diversity and Metabolites in Wholewheat Sourdough.

Wholewheat sourdough products are becoming increasingly more popular, and Staphylococcus aureus is a common opportunistic pathogen in dough products. The effects of S. aureus contamination (102 cfu/g) on metabolites as well as titratable acidity (TTA), pH, and microbial diversity of sourdough were investigated. S. aureus contamination significantly decreased the content of mannose while increasing the sorbitol in sourdough (p < 0.05). The S. aureus contamination significantly reduced the number of lactic acid bacteria (LAB), such as Lactobacillus curvatus, and the TTA values (p < 0.05). Furthermore, S. aureus contamination significantly reduced the content of most esters and acid flavor compounds while significantly increasing the content of 2,4-decadienal (p < 0.05), which is a compound that could have a negative impact on the flavor of sourdough. The PCA model developed based on volatile metabolites data could be used to distinguish contamination of S. aureus in sourdough cultured for 4 h. Sorbitol, 2,3-dimethylundecane, 1-pentanol, and 3-methylbutanoic acid were newly found to be the characteristic metabolites in S. aureus-contaminated sourdough.

Metabolites analysis for cold-resistant yeast (Wickerhamomyces anomalus) strains own antioxidant activity on cold stored fish mince.

The effect of eight cold-resistant yeast strains (J3, J7, J8, J9, J12, J15, J18, and J25) of Wickerhamomyces anomalus on the lipid oxidation of cold stored fish mince (4 °C) were investigated. And the metabolites of these yeast were determined with gas chromatography-mass spectrometry. These strains could effectively inhibit the increase of hydroperoxides value (p < 0.05), and the inhibiting rate was positively correlated with the content of isolongifolene, xylitol, turanose, thymol-glucoside, and uridine. Especially, the J3, J7, J8, J9, J12, and J18 could eliminate a large part of thiobarbituric acid reactive substances (TBARS) (p < 0.05), the eliminating rate was proportionate to the aldehyde dehydrogenase activity. Several bacteriostatic metabolites were detected: thymol-glucoside, 2-phenylethanol, cedro, and 2,4-bis (1,1-dimethylethyl) phenol. In addition, W. anomalus produced many metabolites with fruit and floral notes. In conclusion, cold-resistant W. anomalus strains own antioxidant activity were potential new bio-preservatives in the cold storage of muscle products.

Effect of Saccharomyces uvarum on lipid oxidation and carbonyl compounds in silver carp mince during cold storage.

Fish lipid is highly susceptible to oxidation, resulting in accumulation of toxic substances reactive carbonyl compounds (RCCs), the reduction of nutritional value, and the production of odorous substances. In this study, the effect of yeast (Saccharomyces uvarum) on RCCs, fat acid composition, volatiles, and sensory traits in silver carp mince stored at 4°C was evaluated. Yeast eliminated malondialdehyde, 4-hydroxyl-2-hexenal, and 4-hydroxyl-2-nonenal by about 80%, 68%, and 60%, which increased by about 170%, 340%, and 300% in the control, respectively. Yeast helped retain about 80% of the polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), respectively; only about 53% and 46% of EPA and DHA, respectively, were maintained in the control. Yeast removed off-odors hexanal, nonanal, and decenal, resulting in enhanced sensory traits. These findings were economically important for improving the quality of fish products. It might present an approach to improve the flavor of fish products.

Oryzanol Modifies High Fat Diet-Induced Obesity, Liver Gene Expression Profile, and Inflammation Response in Mice.

In Western countries and China, the dietary habit of high calories usually results in hyperlipidemia, which is closely associated with cardiovascular diseases. In the study, we investigated the antihyperlipidemic effect of oryzanol and its molecular mechanism in the high fat diet (HFD) mouse model. In total, 60 ICR mice were randomly divided into control group, HFD group, and HFD+Ory group. The mice from the HFD+Ory group were additionally fed with 100 mg/kg of oryzanol by intragastric administration. Our data indicated that oryzanol treatment for 10 weeks significantly reduced bodyweight, liver weight, and adipose tissues weight of the mice; lowered the contents of total cholesterol (TC), triglycerides (TG), and low density lipoprotein-cholesterol (LDL-C); and elevated high density lipoprotein-cholesterol (HDL-C) in the plasma of HFD mice. Compared with the HFD group, H&E staining showed that oryzanol treatment decreased the size of fat droplets of liver tissues and the size of adipocytes. Gene chip data found that oryzanol administration caused 32 genes to increase expressions while 60 genes had reduced expressions in the liver tissues of HFD mice. IPA software was used to analyze the protein interaction network and found that transcript factor NF-κB located in the central role of network, meaning NF-κB may have important function in the lipid-lowering effect of oryzanol. Western blotting and RT-qPCR confirmed that lipid metabolism-related gene expressions were obviously regulated by oryzanol administration. Oryzanol also inhibited expressions of inflammatory factor in the liver tissues of HDF mice. Taken together, our data indicate that oryzanol treatment can regulate lipid metabolism-related gene expressions and inhibit HDF-caused obesity in mice.