Impact of thermal processing and emulsification methods on spice oleoresin blending: Insights for flavor release and emulsion stability.

This study investigated the effect of heat treatments on the pungency and aroma profiles of a spice oleoresin blend, and the emulsion stability with different surfactants, encapsulating agents, and homogenization mechanisms. Total pungency increased with heat until 120 °C and drastically reduced at 150 °C. Thermal processing induced aroma release, and 46 compounds were identified at 90 °C, predominantly comprising sesquiterpenes. Tween 80 dispersed the highest oleoresin mass (6.21 ± 0.31 mg/mL) and reported the maximum emulsion stability index. The oleoresin percentage significantly influenced the emulsion stability, with 1% oleoresin producing the most stable emulsion. High-pressure homogenization applied on gum Arabic resulted in a greater encapsulation efficiency, exceeding 86%, and the lowest creaming index (4.70 ± 0.06%), while Hi-Cap 100 produced the best flow properties. The findings provide insights into incorporating lipophilic spice oleoresin blends in aqueous food systems and understanding the release of flavor compounds during thermal food processing.

Characterization and modeling of diffusion kinetics of rosemary oleoresin extract from gellan gum-based film.

Fresh food products are highly prone to oxidation and microbial attack, rendering them unsuitable for consumption. Thus, active food packaging was developed to protect and prolong food shelf-life. Zein/gellan gum (GG) based active film is developed by incorporating rosemary oleoresin extract (ROE) (0-20%). The films were characterized by their barrier and antioxidant properties. The release behavior of ROE in fatty and hydrophilic food stimulants was investigated via mathematical modeling. The active films incorporated with 20% ROE have significantly higher oxygen barrier and oxygen transfer is reduced by 20% compared to the control. A tortuous path is created with ROE, which impedes oxygen movement across the film. ROE addition improved water resistance performance by reducing the active film swelling ratio by 31%. This improvement is attributed to the hydrophobic nature of ROE. FTIR shows that the interaction between ROE and the active film is primarily hydrogen bonding and electrostatic interactions. Active film exhibits excellent antioxidant activity, with high TPC, DPPH scavenging activity, and FRAP. Mathematical modeling revealed a higher diffusivity (D) of ROE in fatty food stimulants at 24 °C, attributed to high polarity and solubility in fatty food stimulants. Overall, this active film has an excellent antioxidant effect and could potentially be used as food packaging for high-fat food products to prevent oxidation.

Encapsulation of Hydrophobic Apigenin into Small Unilamellar Liposomes Coated with Chitosan Through Ethanol Injection and Spray Drying.

Despite the multiple health benefits, natural flavonoid apigenin has poor aqueous solubility that restricts its delivery in foods. This study investigated the potential of spray-dried chitosan-coated liposomes prepared from scalable methods for the food industry as the delivery carriers for apigenin. Apigenin-loaded small unilamellar liposomes produced from ethanol injection had an encapsulation efficiency of 74.88 ± 5.31%. They were electrostatically stabilised via chitosan coating (0.25% w/v) and spray-dried. Spray-dried chitosan-coated apigenin liposomes (SCAL) exhibited the following powder characteristics: yield 66.62 ± 3.08%, moisture content 4.33 ± 0.56%, water activity 0.2242 ± 0.0548, particle size 10.97 ± 1.55 µm, nearly spherical morphology with wrinkles and dents under microscopic observation. Compared with the unencapsulated apigenin, SCAL demonstrated improved aqueous solubility (10.22 ± 0.18 mg/L), higher antioxidant capacity, and stability against simulated gastrointestinal digestion. The chitosan coating gave a slower in-vitro release of apigenin in SCAL (77.0 ± 6.2%) than that of uncoated apigenin liposomes (94.0 ± 5.3%) at 12 h. The apigenin release kinetics from SCAL could be represented by the Korsmeyer-Peppas model (R2 = 0.971). These findings suggest that SCAL could be a promising delivery system of apigenin for functional food applications.

Impact of ozone treatment on the physico-chemical properties, bioactive compounds, pectin methylesterase activity and microbiological properties of watermelon juice.

The increasing consumer demand for higher quality fruit juices has encouraged the use of non-thermal processing to extend the shelf life of perishable juice, watermelon juice. Ozone with its high oxidizing effect serve as an effective non-thermal processing treatment. The aim of this study was to investigate the impact of ozone treatment on the physico-chemical, bioactive compounds, pectin methylesterase (PME) activity and microbiological properties of unclarified and clarified watermelon juice. The ozone gas was pumped into watermelon juice for up to 25 min in a closed chamber. The microorganism inactivation in unclarified and clarified watermelon juices improved across the increasing processing time. Among these juices, the microorganism inactivation efficiency of ozone was found higher on clarified juice (3.466 log) than unclarified juice (3.150 log). It was found that °Brix value and PME activity were not altered by ozone treatment. The other physico-chemical properties (titratable acidity, pH, total colour difference, non-enzymatic browning, cloudiness) and bioactive compounds reduced across processing time. This study demonstrated that ozone treatment is an effective non-thermal processing technique to reduce the microorganism in watermelon juice. Further study is required to optimise the processing parameters of ozone treatment to maintain the overall quality of the watermelon juice.

Palm Olein Organogelation Using Mixtures of Soy Lecithin and Glyceryl Monostearate.

The present work investigated the interaction between soy lecithin (SL), glyceryl monostearate (GMS), and water in structuring palm olein (PO) to create an organogel having similar mechanical properties to commercial spread. Extreme vertices mixture design was used to optimize the composition of PO-based organogel. The resulting model showed a good fit to the predicted data with R2 ≥ 0.89. The optimum composition was 8% SL, 22% GMS, 28% water, and 42% PO (w/w) to produce a mean firmness of 1.91 N, spreadability of 15.28 N s-1, and oil binding capacity (OBC) of 83.83%. The OBC of optimized organogel was 10% higher than commercial spread product, and no significant difference was observed in the mechanical properties (p > 0.05). The microstructure, as well as the rheological and thermal properties of the optimized organogel were characterized. Fourier transform infrared analysis indicated that hydrogen bonding and van der Waals interactions were the key driving forces for organogelation. The mixture of SL and GMS favored the formation of ß' + ß form crystals with a predominance of the ß' form. These results have important implications for the development of PO-based organogel as a potential fat replacer in the production of low-fat spread.

Stability and recovery of cyclodextrin encapsulated catechin in various food matrices.

Catechin is astringent in taste, sparingly soluble in water and sensitive to oxygen, light and pH. These properties restrict its application in food products. The present study investigated the stability of inclusion complex (IC) and catechin in various food matrices and investigated in vitro recovery profile of catechin and IC in liquid, semi-solid and solid food matrices. Besides, the sensory profile of IC added yogurt was also determined. Results showed that IC and catechin was more stable in solid matrix compared to semi-solid and liquid matrices. IC added in milk and yogurt show the highest percentage recovery of catechin compared to IC added in cheese and catechin added in all the matrices in in vitro digestive system. Through IC, ß-CD masked the bitterness of catechin. These results suggest that protection of antioxidant such as catechin by ß-CD inclusion complex may have applications in functional foods and health supplements.

Studies on the storage stability of fermented red dragon fruit (Hylocereus polyrhizus) drink.

The objective of this work was to study the effect of storage temperatures and duration on the stability of fermented red dragon fruit drink (FRDFD) on its betacyanins content, physicochemical and microbiological qualities (BPM) and determining sensory acceptability. Results showed that both storage temperatures and duration have a significant effect on betacyanins content and physicochemical properties of FRDFD. Aerobic mesophilic and yeast and mold counts were lower than 1 × 103 CFU/mL for FRDFD stored at both temperatures. The loss of betanin (16.53-13.93 g/L) at 4 °C was 15.73% with no significant changes in physicochemical properties from week two onwards compared to 56.32% (16.53-7.22 g/L) of betanin loss at 25 °C. At week eight, FRDFD stored at 4 °C still contained 13.93 g/L betanin with a pH value of 3.46, suggested its potential as a functional drink which is sensory acceptable (mean score > 80% using hedonic test) among consumers.

Academic burnout and eating disorder among students in Monash University Malaysia.

This study examined the prevalence of academic burnout and the relationship between academic burnout and eating disorder among Monash university students for a period of one year. One hundred and thirty-two participants were recruited for the study via advertisement. They were invited to complete three instruments, namely Demographic Questionnaire, Maslach Burnout Inventory - Student Survey (MBI-SS) and Three Factor Eating Questionnaire-Revised 18-item (TFEQ-18). In addition, anthropometric measurements such as weight, height, body mass index (BMI), body fat percentage and waist circumference were taken. All data were collected at baseline and after 6-8weeks. Analysis of Variance (ANOVA), Kruskal-Wallis and Bonferroni pairwise comparison tests were performed using Stata version 13. The prevalence of academic burnout after 6-8weeks was revealed to be 17.4% and 73.5% respectively for moderate and high level of academic burnout respectively. Emotional eating (EEat) scores were significantly different over levels of academic burnout after 6-8weeks (p=0.0103) while no significant differences was observed in other subscales such as cognitive restraint (CR) and uncontrolled eating (UE). These findings evidenced partial associations between academic burnout and eating disorder.

Ultrasound-assisted extraction of antioxidants in Misai Kucing (Orthosiphon stamineus).

Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and extraction time (min). Antioxidant compounds were determined by total phenolic content and total flavonoid content to be 1.4 g gallic acid equivalent/100 g DW and 45 g catechin equivalent/100 g DW, respectively. Antioxidant activities were evaluated using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical scavenging capacity assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging capacity assay to be 1,961.3 and 2,423.3 µmol Trolox Equivalent Antioxidant Capacity (TEAC)/100 g DW, respectively. Based on the optimal conditions, experimental values were reported to be close to the predicted value by RSM modeling (p>0.05), indicating the suitability of UAE for extracting the antioxidants of Misai Kucing. Rosmarinic acid, kaempferol-rutinoside and sinesetine were identified by high performance liquid chromatography-mass spectrometry.

Optimal binary solvent extraction system for phenolic antioxidants from mengkudu (Morinda citrifolia) fruit.

Antioxidants have been widely used in the food industry to enhance product quality by preventing oxidation of susceptible substances. This work was carried out to maximise the recovery of total phenolic content (TPC), total flavonoid content (TFC), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging capacity and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging capacity from Morinda citrifolia fruit via modification of the ethanol concentration, extraction time and extraction temperature at minimal processing cost. The optimised conditions yielded values of 881.57 ± 17.74 mg GAE/100 g DW for TPC, 552.53 ± 34.16 mg CE/100 g DW for TFC, 799.20 ± 2.97 µmol TEAC/100 g DW for ABTS and 2,317.01 ± 18.13 µmol TEAC/100 g DW for DPPH were 75% ethanol, 40 min of time and 57 °C. The four responses did not differ significantly (p > 0.05) from predicted values, indicating that models obtained are suitable to the optimisation of extraction conditions for phenolics from M. citrifolia. The relative amounts of flavonoids were 0.784 ± 0.01 mg quercetin/g of extract and 1.021 ± 0.04 mg rutin/g of extract. On the basis of the results obtained, M. citrifolia extract can be used as a valuable bioactive source of natural antioxidants.

Antioxidant synergism between ethanolic Centella asiatica extracts and α-tocopherol in model systems.

The synergistic antioxidant effects of ethanolic extracts of Centella asiatica (CE), and α-tocopherol have been studied. The types of interactions exhibited by CE and α-tocopherol combined at different ratios were measured using three assays: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical-scavenging capacity, the ß-carotene bleaching system and liposome peroxidation assays. Fixed-fraction isobolographic analysis was used to detect any inducement of the antioxidant activity compared with the individual activities of CE and α-tocopherol. Of all synergistic combinations of CE and α-tocopherol, only fraction 2/3 showed the synergistic combination that fits well in three different assays and can be explained by the regeneration of α-tocopherol by CE despite the interaction effect of ß-carotene present in the analytical assay. This phenomenon involved complex interactions between CE and α-tocopherol to exhibit different degrees of interactions that eventually increased antioxidant activity.