PRACTICAL APPLICATIONS: In general, juice concentrate is a better form of food for transportation, preservation, and ingredient. Models are necessary to predict the effects of processing factors such as concentration and temperature on the rheological behavior of juice concentrates. The modeling approach allows prediction of behaviors and determination of processing parameters. The master curve model introduced in this study simplifies and generalized rheological behavior of juice concentrates over a wide range of concentration when temperature factor is insignificant. The proposed new mathematical model from the combination of the Arrhenius and logistic sigmoidal growth models has improved and extended description of rheological properties of fruit juice concentrates. It also solved problems of negative values of consistency coefficient and flow behavior index prediction using existing model, the Arrhenius equation. These rheological data modeling provide good information for the juice processing and equipment manufacturing needs.
METHODS: Participants were 997 university undergraduate students, with a mean age of 21 years (SD = 1.58). The majority of the participants (80.4%) were female. Health-promoting behaviour was assessed using the 52-item HPLP-II, which measures six components of health-promoting behaviour outcomes. HPLP-II was translated into the Malay language using standard forward and backward translation procedures. Participants then completed the HPLP-II Malay version (HPLP-II-M). Confirmatory factor analysis (CFA) was conducted using Mplus 8.0 software on the six domains of HPLP-II-M model.
RESULTS: The CFA result based on the hypothesised measurement model of six factors was aligned with the original HPLP-II, except for two low loading items which were subsequently removed from the CFA analysis. The final CFA measurement model with 50 items resulted in a good fit to the data based on RMSEA and SRMR fit indices (RMSEA = 0.046, 90%CI = 0.045, 0.048, SRMR = 0.062). The construct reliabilities for the HPLP-II-M subscales were acceptable, ranging from 0.737 to 0.878.
CONCLUSION: The HPLP-II-M with six components of health-promoting behaviour outcomes and 50 items was considered valid and reliable for the present Malaysian sample.
METHODS: ACE inhibitory proteins were isolated from P. cystidiosus based on the bioassay guided purification steps, i.e. ammonium sulphate precipitation, reverse phase high performance liquid chromatography and size exclusion chromatography. Active fraction was then analysed by LC-MS/MS and potential ACE inhibitory peptides identified were chemically synthesized. Effect of in vitro gastrointestinal digestions on the ACE inhibitory activity of the peptides and their inhibition patterns were evaluated.
RESULTS: Two potential ACE inhibitory peptides, AHEPVK and GPSMR were identified from P. cystidiosus with molecular masses of 679.53 and 546.36 Da, respectively. Both peptides exhibited potentially high ACE inhibitory activity with IC50 values of 62.8 and 277.5 μM, respectively. SEC chromatograms and BIOPEP analysis of these peptides revealed that the peptide sequence of the hexapeptide, AHEPVK, was stable throughout gastrointestinal digestion. The pentapeptide, GPSMR, was hydrolysed after digestion and it was predicted to release a dipeptide ACE inhibitor, GP, from its precursor. The Lineweaver-Burk plot of AHEPVK showed that this potent and stable ACE inhibitor has a competitive inhibitory effect against ACE.
CONCLUSION: The present study indicated that the peptides from P. cystidiosus could be potential ACE inhibitors. Although these peptides had lower ACE inhibitory activity compared to commercial antihypertensive drugs, they are derived from mushroom which could be easily obtained and should have no side effects. Further in vivo studies can be carried out to reveal the clear mechanism of ACE inhibition by these peptides.