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Item Targeted dairy fortification: leveraging bioactive compounds to enhance nutritional value(Taylor and Francis Group, 2025-06-30) Bagheri H; Akhavan-Mahdavi S; Sarabi-Aghdam V; Mirarab Razi S; Singh Beniwal A; Rashidinejad ADairy products, rich in nutrients, are crucial for human health and disease prevention. Recent trends focus on enhancing their nutritional value by fortifying them with bioactive compounds from plant and animal sources. Scientific evidence suggests these compounds can improve public health by potentially treating and preventing diseases, including cancer. This systematic review discusses advances in dairy product fortification with health-promoting compounds, highlighting their role in correcting nutritional deficiencies and reducing chronic disease risk. Innovative delivery systems are being developed to improve the stability and functionality of these compounds in fortified dairy products. Despite challenges in maintaining the physical, textural, and sensory qualities of dairy products, fortification is a promising public health strategy. The review calls for interdisciplinary research to better understand the bioavailability, effectiveness, and long-term health impacts of bioactive compounds in dairy foods. Such research could inform best practices and policy recommendations. Using dairy products as carriers for bioactive compounds can significantly improve nutritional status and reduce the global burden of chronic diseases, making it a strategic approach to public health nutrition. This review cautiously evaluates current evidence, particularly regarding chronic disease prevention, and emphasizes the need for further research on specific populations, such as children and the elderly.Item Development of microemulsion delivery systems for bioactive compounds : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Food Technology at Massey University, Auckland, New Zealand(Massey University, 2020) Yuan, QuanMany bioactive compounds for health benefits are not readily stable against degradation and their solubility is also very low. As a result, a delivery system is required to encapsulate and protect bioactive compounds for their food applications. Emulsion is one of the delivery systems which has been studied by many researchers. But emulsion tends to destabilize during storage and its opaque optical properties makes it difficult for its use and incorporation into clear foods or beverages without affecting their original appearance. Therefore, microemulsion, which is known to be transparent, has been investigated to some extent to encapsulate and deliver bioactive compounds as a potential delivery system. The objective of this research was to fabricate oil-in-water (O/W) microemulsions which might be utilised as the delivery system for bioactive compounds. This thesis is mainly composed of two sections. The first section was to produce microemulsions via emulsion dilution method and water titration method as well as to study the characteristics of these microemulsions. Beta-carotene was a type of bioactive compound used in the second section to study the effect of beta-carotene on the formation and properties of microemulsion which was fabricated using the same methods described above. At first, emulsion dilution method was employed to fabricate microemulsions with different types and concentrations of oils, such as peanut oil, fractionated coconut oil, isopropyl myristate (IPM), lemon oil and Capmul 708G, and also with different surfactants (Tween 20, 40, 60 and 80). It was found that peanut oil and fractionated coconut oil could not be utilised to form microemulsions by this method, whereas IPM and lemon oil had the ability to fabricate microemulsions. When 1% Tween 80 was introduced as the surfactant and dilution medium, microemulsion could be formed when the concentration of IPM was less than 0.1% and that of lemon oil was less than 0.2%. Among the different types of Tween surfactants, Tween 80 was the most efficient when its solution containing Tween micelles was used as a dilution medium compared to the other Tween surfactants because more lemon oil could be incorporated into the Tween 80 micelles with an increase in Tween 80 concentration. In the following study, a water titration method was employed to create ternary or pseudo phase diagrams which indicated the ability to fabricate microemulsions of a mixture system. Various types of oils (Captex 100, Capmul PG-8, Capmul PG-12, Capmul PG-2L, lemon oil, Capmul MCM C8, Capmul 708G and Captex 355) and surfactants (Tween 80, Tween 20, Span 80 and Kolliphor EL) were used in this study. Absolute ethanol and propylene glycol (PG) were also incorporated as cosurfactant and cosolvent, respectively. It is concluded that all these oils and surfactants could be utilised by the water titration method to produce microemulsions, however, their ability to form microemulsions were different. Capmul 708G, which is a monoglyceride, was the most efficient in terms of producing microemulsions compared to diglyceride and triglyceride. Tween 20 and Kolliphor had the similar emulsifying properties compared to Tween 80 whereas Span 80 was not efficient. Both absolute ethanol and PG could assist the formation of microemulsions when they were introduced into the mixture system of oil, surfactant and water. In the following study, microemulsions containing 0.1% and 0.4% lemon oil and an emulsion containing 1.5% lemon oil (larger oil droplets), which were fabricated by the emulsion dilution method, were chosen to incorporate beta-carotene as a lipophilic model bioactive compound into lemon oil in order to study its impact on the formation and properties of the resulting microemulsion and emulsion systems. The encapsulation of beta-carotene into 0.1% and 0.4% lemon oil caused a significant increase in the particle size of the O/W microemulsions, but the particle size was still within the size range of microemulsion. As a result, the beta-carotene-loaded microemulsions containing 0.1 and 0.4% lemon oil were visually clear in appearance. However, the incorporation of beta-carotene did not increase and alter the particle size of the emulsion containing 1.5% lemon oil. The microemulsion sample containing 0.1% lemon oil and the emulsion containing 1.5% lemon oil were stored at 25 °C without exposed to oxygen and light for one month. While, the microemulsion containing 0.4% lemon oil was selected and placed at three different temperatures (4, 25 and 37 °C) for 1 month: at 4 and 37 °C without exposure to both oxygen and light and at 25 °C, four different environmental conditions (i.e. with oxygen/light, with oxygen and without light, without oxygen and with light, without oxygen/light). The results showed that the rate of beta-carotene degradation was lower in all these three samples when compared to the beta-carotene present in a hexane solution without encapsulation. Higher temperature accelerated the degradation rate of beta-carotene. As a consequence, the 0.4% lemon oil microemulsion at 4 °C exhibited the slowest degradation rate of beta-carotene. Next, the microemulsions fabricated by the water titration method were selected to encapsulate beta-carotene to study the encapsulation capacity of these microemulsion systems as well as their ability to protect beta-carotene against oxidative degradation during storage. Capmul 708G, Tween 80, Milli-Q water and PG mixture system were chosen to fabricate microemulsions and two formulations (L910 and L990) were prepared to incorporate beta-carotene. L910 was comprised of 81% Capmul 708G, 9% Tween 80, 5% water and 5% PG, whereas L990 contained 9% Capmul 708G, 1% Tween 80, 45% water and 45% PG. It was able to see clearly from this experiment that the L910 system could incorporate more beta-carotene than L990. Both L910 and L990 could reduce the degradation rate of beta-carotene when loaded into them compared to their presence in hexane solutions without encapsulation. Similar to the previous experiment as described above, when the beta-carotene incorporated microemulsions were placed at 4 °C and away from oxygen and light, beta-carotene had the highest retention rate after storage for 1 month. Furthermore, beta-carotene degradation rate in L910 was slower than that in L990, indicating L910 was more effective than L990 in terms of incorporating and protecting beta-carotene. It is shown clearly from the present study that microemulsions could be formed via the water titration and emulsion dilution methods. The type and concentration of oil phase and surfactant had a significant influence on the determination of whether a mixture system could form a microemulsion as well as the properties of the formed microemulsion. The microemulsions produced by these two different methods could be utilised to encapsulate beta-carotene as the incorporation of beta-carotene did not have a significant influence on the properties of the original microemulsions. Moreover, microemulsions provided the stability and protection to beta-carotene against oxidative degradation that could be caused by oxygen, light and temperature during storage, which might be possible to be applied to some liquid foods and beverages.Item Development of a novel functional yogurt containing anti-inflammatory bioactive compounds : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Food Technology, Massey University, Albany, New Zealand(Massey University, 2019) Bisht, AkshayThe consumption of bioactive compounds is increasingly becoming popular due to their beneficial effects on health and wellbeing. The anti-inflammatory properties of bioactives such as curcumin are well established. However, curcumin has low bioavailability, hence it is frequently consumed in capsules to enable the delivery of the required dosage to achieve optimum health benefits. Synergistic effects may be achieved by combining curcumin with other anti-inflammatory bioactive compounds. Recent investigations on lupeol and chlorogenic acid (CGA) have reported that these bioactive compounds show similar therapeutic benefits to curcumin. Furthermore, delivery of bioactives via a food matrix, such as fermented coconut yogurt, may improve bioavailability. Thus, this research investigated the potential of an anti-inflammatory combination of curcumin with CGA or lupeol with the objective of developing coconut yogurt to deliver the combined bioactives to humans. This research was performed in two parts. In part 1, the anti-inflammatory potential of three bioactive compounds (curcumin, CGA and lupeol), individually and in combination, was investigated using an in vitro model of human THP-1 macrophages stimulated with LPS. Differentiated THP-1 cells were treated with variable concentrations of curcumin, CGA and lupeol and their effects on the production of TNF-α, a pro-inflammatory cytokine, and cell viability was measured using ELISA and MTT assays, respectively. Curcumin alone significantly (p≤0.05) suppressed TNF-α production in a dose dependent manner. Curcumin in combination with lupeol gave an additional 15-35 % reduction in TNF-α level. However, the reduction in TNF-α production by curcumin + lupeol was accompanied by cell death. In contrast, treatment with CGA appeared to protect the THP-1 cells from LPS toxicity and its co-administration with curcumin at a 1:1 ratio reduced TNF-α production without impacting cell viability. Further, it is proposed that the latter combination showed anti-inflammatory activity by reducing mRNA expression of pro-inflammatory cytokines and COX-2 enzyme via suppressing NF-κB, IκB-β-kinase and TLR-4 receptor. Thus, a 1:1 combination of curcumin with CGA was selected to be delivered in coconut yogurt. In part 2, coconut yogurt enriched with turmeric and coffee to deliver the benefits of curcumin and CGA, respectively, was developed. Addition of 100 mg of each bioactive compound to 150 g coconut cream did not have any significant (p≤0.05) effect on the viable cell counts of the yogurt culture, pH and titratable acidity during fermentation. However, slight changes in pH, titratable acidity, viable cell counts and colour were noted during refrigerated storage of the yogurt for 15 days; no changes in syneresis was observed in the control and bioactive added samples. By the end of the storage period, 63.31±3.20 % and 84.81±3.17 % of curcumin and CGA, respectively, were retained in the yogurt samples. The yogurt samples with added bioactive compounds were well accepted by consumer sensory evaluation panellists. Thus, from the obtained data it can be concluded that coconut yogurt may be a potential delivery medium for health promoting curcumin and CGA to consumers.Item Complexation between whey protein and octenyl succinic anhydride modified starch: a novel approach for encapsulation of lipophilic bioactive compounds : a thesis presented in partial fulfilment of the requirements for the degree of Master of Food Technology at Massey University, Manawatū, New Zealand(Massey University, 2018) Wu, DanProteins and polysaccharides are frequently used in food industry, and their interactions in food systems could affect the properties of food products such as the texture and stability. Therefore, the knowledge of the interactions between these two macromolecules is of great significance for food manufacturers. The aim of this study was to investigate the complexation process between whey protein isolate (WPI) and octenyl succinic anhydride (OSA)-modified starch and explore the application of their interactions in the encapsulation of lipophilic bioactive compounds. The formation of complexes between WPI and OSA-modified starch was investigated as a function of pH (7-3), the heat treatment of WPI, and the concentration ratio of WPI and OSA-modified starch (1:1, 1:10 and 1:20). The complexation process was evaluated by the determinations of the absorbance, particle size and ζ-potential of the mixtures, which were determined by spectrophotometer and dynamic light scattering. It was found that the OSA-modified starch was more likely to interact with heated WPI (HWPI, 90°C for 20 min) rather than non-heated WPI (NWPI). The optimum condition for the formation of insoluble coacervates was at ratio of 1:10 and pH 4.5, which was driven by both electrostatic and hydrophobic interactions. The structure of the complexes formed under the optimum condition could be affected by different molecular characteristics of OSA-modified starch including molecular weight (Mw) and degrees of substitution (DS) value. It was found that OSA-modified starch with higher Mw was difficult to form a dense precipitation phase with HWPI due to its higher viscosity restricting the movement of any particles present. Stable soluble complexes could be formed between HWPI and OSA-modified starch with higher DS value under the same condition, which may be attributed to the stronger steric hindrance of OSA-modified starch with higher DS values. It seems that the complexation between HWPI and OSA-modified starch was induced by electrostatic interactions, while the structural properties of the complexes were determined by hydrophobic interactions. The soluble complexes between HWPI and OSA-modified starch with a DS value of 4.29 ± 0.11% formed at ratio of 1:10 and pH 4.5 were applied to encapsulate β-carotene, which was used as a model of lipophilic bioactive compounds in this study. The apparent aqueous solubility of β-carotene was enormously improved (264.05±72.53 μg/g) after encapsulation in the soluble complexes. No significant differences were observed under transmission electron microscopy (TEM) and scanning electron microscope (SEM) between the soluble complexes before and after encapsulation of β-carotene whether in a liquid or a powdered form. Results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) indicated that the β-carotene was in an amorphous form loaded inside the soluble complexes, which suggested that the molecules of β-carotene evenly distribute within the complex particles by hydrophobic force. In addition, the β-carotene-loaded freeze-dried soluble complexes showed good redispersion behaviour and a high retention rate of the loaded β-carotene (89.75%), which indicated that the β-carotene-loaded soluble complexes could be successfully converted into a powdered form. The accelerated stability study showed that these soluble complexes could effectively protect the loaded β-carotene at pH 4.5 during storage, especially after 7 days of storage. This indicated the potential of using the soluble complexes between HWPI and OSA-modified starch to protect lipophilic bioactive compounds for long-term storage under low pH conditions. This study may be beneficial for the potential using the soluble complexes between HWPI and OSA-modified starch as delivery systems for lipophilic bioactive compounds in commercial applications.Item Bioactivity of food-grade curcuminoids and their incorporation into coconut yogurt : a thesis submitted in partial fulfilment of the requirements for the degree of Masters of Food Technology, Massey University, Albany, New Zealand(Massey University, 2018) Singh, TaniaCurcuminoids are the bioactive components of turmeric, which comprises pf of 77% curcumin, 17% demethoxycurcumin (DMC) and 3% bisdemethoxycurcumin (BDMC). The application of curcuminoids is limited by its low oral bioavailability due to poor aqueous solubility, low absorption from the gut, rapid metabolism and rapid systemic elimination, which can be improved by incorporating curcuminoids into a suitable food matrix. Thus, the present study aimed at developing a coconut yogurt as a potential vehicle for the delivery of bioactive curcuminoids. This research project was carried out in three phases. Phase I involved the screening of 10 different commercial food-grade curcuminoid products in three types of yogurt. Each of the 10 food-grade curcuminoid products, were added (0.4% w/w) to three types of commercial yogurt: cow’s milk yogurt, coconut cream yogurt and a goat’s milk yogurt and subjected to pH measurement and sensory evaluation with a view to selecting the most promising curcuminoid and delivery medium. Results showed that coconut yogurt with added curcuminoids (C7 and C9) were the most acceptable to the sensory panellists. In phase 2, the two selected curcuminoid products (C7 and C9) were subjected to a cell-based, in vitro analysis to measure their anti-inflammatory activity and cytotoxicity using THP-1 macrophages stimulated with lipopolysaccharide (LPS). The anti-inflammatory activity of the two curcuminoid products was compared to analytical grade curcumin (Pure C) as positive control and a dimethyl sulfoxide (DMSO) vehicle control. C7 and C9, as well as pure curcumin presented a varied degree of toxicity towards LPS stimulated macrophages, as measured by the MTT (3-(4,5- Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) colorimetric assay. All curcuminoid samples were found to be non-toxic to THP-1 cells at 10 µM. At this concentration, the test products and the control down-regulated the expression of TNF-α by 2.5-fold in the differentiated THP-1 cells stimulated with LPS. Concentrations of DMSO as high as 0.5% were well tolerated by the macrophages. As there were no significant differences (p>0.05) in the anti-inflammatory activity of the food-grade curcuminoid samples, the both the test products in coconut cream yogurt were tested in phase III. Samples of coconut cream were fortified with food-grade curcuminoids (C7 and C9) at 400 mg/150g, prior to yogurt fermentation; a negative control without curcumin was also included. The physico-chemical, microbiological and sensory properties of the fermented coconut cream yogurts were compared to the control coconut yogurt. Results showed curcuminoids did not have any effect on fermentation of coconut cream. During storage (4°C) for 15 days, acidity, yogurt microflora and syneresis of the curcuminoid enriched yogurts were not significantly different from the control yogurts. However, addition of curcuminoids resulted in formation of a weaker gel compared to the control yogurt, and the viscosity of the gels varied during storage. The concentrations of curcuminoids in the coconut cream yogurt during storage of the fermented products were measured by reversed phase HPLC. HPLC analysis showed that 70-75% of the bioactives were retained in the yogurt at the end of the 15-day storage period. The two fermented coconut yogurts fortified with curcuminoids (C7 and C9) were well-accepted by a consumer sensory panel (n=180). Based on the pH, acidity, sensory, texture, microbiological and HPLC results, it can be inferred that coconut yogurt may serve as a suitable delivery medium for bioactive curcuminoids.