Emulsions have garnered significant attention within a variety of industries, including pharmaceuticals, food production, and cosmetics. The importance of emulsions across these sectors is attributed to their versatility and unique properties, such as increased interfacial area and the ability to deliver compounds insoluble in water or to mask the flavor of unpalatable ingredients. A comprehensive and precise assessment of the physicochemical properties, structural features, and stability of emulsions is an indispensable phase in the pursuit of new formulations and the improvement of manufacturing protocols. The characterization of emulsions encompasses an array of methodologies designed to determine their attributes, such as droplet size, distribution, concentration, surface charge, and others. In this review, we explore the techniques most frequently used to characterize emulsions and critically assess the significance each method holds in understanding the behavior and predicting the stability of emulsions. We elucidate the basic principles of these methods while emphasizing what information can be gathered from them, and how to effectively interpret this information to optimize the properties of emulsions, crucial from the standpoints of food and other industries, such as long-term stability and easy processing.
In this research, stabilisation of oil-in-water emulsions with non-chemically modified gelatinised starch is presented. Thus far only octenyl succinic anhydride (OSA) modified gelatinised starch has been known to adsorb at emulsion droplet interfaces, acting as emulsifiers. Screening a range of commercially available food starches revealed that a non-waxy rice starch, a waxy rice starch and the waxy maize starch PRIMA600 showed oil-in-water emulsifying ability following gelatinisation. The microstructure of emulsions formulated with 20% oil and 1% starch was stable for at least 3 months. Thermal, crystallinity and molecular property analyses as well as amylose and protein content revealed no obvious link to this property. Nevertheless, this research has provided the food industry with exciting results for the formulation of clean label emulsions. Moreover, it presents a concept for oral release food emulsions with destabilisation via salivary amylase digestion of the stabilising starch emulsifier.
Gelatinized wheat, potato and waxy maize starches were treated enzymatically in order to increase the degree of branching of the amylopectin fraction and thereby change the starch degradation profile towards a higher proportion of slowly digestible starch (SDS). The materials were characterized by single-pulse 1H HR-MAS NMR spectroscopy and in vitro digestion profile according to the Englyst procedure. Using various concentrations and incubation times with branching enzyme (EC 2.4.1.18) without or with additional treatment with the hydrolytic enzymes; β-amylase (EC 3.2.1.2), α-glucosidase (EC 3.2.1.20), or amyloglucosidase (EC 3.2.1.3) the proportion of α-(1-6) linkages was increased by up to a factor of 4.1, 5 and 5.8 in waxy maize, wheat and potato starches, respectively. The proportion of SDS was significantly increased when using hydrolytic enzymes after treatment with branching enzyme but it was only for waxy maize that the proportion of α-(1-6) bonds and the in vitro digestion profile was significantly correlated.
In this study, we investigated the effects of furcellaran–gelatine (FUR/GEL) coatings incorporated with herb extracts on the quality retention of carp fish during refrigeration. Nutmeg, rosemary, thyme, milfoil, marjoram, parsley, turmeric, basil and ginger were subjected to water and ethanol extraction methods (10% concentration of herbs). The water extractions of the rosemary and thyme (5%) were used for the further development of coatings due to their high 2,2-Diphenyl-1-picrylhydrazyl (DPPH: 85.49 and 83.28%) and Ferric Reducing Antioxidant Power Assay values (FRAP: 0.46 and 0.56 mM/L) (p < 0.05), respectively. A new, ready-to-cook product with the coatings (carp fillets) was evaluated regarding quality in terms of colour parameters, texture profile, water activity, Thiobarbituric Acid Reactive Substances (TBARSs) and sensory analyses during 12 days of storage at 4 °C. The results show that the colour of the carp fillets treated with the rosemary and thyme extracts became slightly darker and had a propensity towards redness and yellowness. In contrast to the control group, the carp fillets stored in the coatings with the rosemary extract effectively slowed the lipid oxidation processes. Therefore, the innovative coatings produced from carp processing waste may have high potential as components in convenience food products and could extend the shelf-life of carp fillets during refrigerated storage. However, further research is needed to assess the microbiological stability of the obtained food products.