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The pandan (Pandanus amaryllifolius) leaf is commonly used as a food coloring and flavoring agent. Aqueous pandan leaf extract has no foaming properties and deteriorates quickly. Finding the appropriate foaming agent and stabilizer during drying is a challenge. The objective of this research was to investigate the effect of Methocel™, maltodextrin, sodium chloride (NaCl), and pH on foaming properties and foam-mat drying of aqueous pandan leaf extract. Foaming properties of an aqueous extract from fresh pandan leaves were elucidated using Methocel™ K4M (1 and 1.5% w/w) as a foaming agent, maltodextrin (0, 5, 10 and 15% w/w) as a stabilizer, and NaCl (0, 3, and 5% w/w) as a foam improver. The foamed pandan leaf extract was dried using a batch-type cabinet dryer. The results showed that the appropriate concentrations of Methocel K4M™, maltodextrin, and NaCl were 1% or 1.5%, 15%, and 5% (w/w), respectively. Increasing the maltodextrin concentration in combination with NaCl significantly affected the foam density, foam overrun, and foam drainage volume of the pandan leaf extract (p<0.05). Adjusting the pH of the foam solution to 6.2-7.2 maintained the chlorophyll content during drying better than the control (p<0.05).

Foam‐mat freeze‐drying (F‐FD) of aqueous pandan extract with various foaming agents (egg white protein, sodium caseinate, and METHOCEL) was carried out to improve the process conditions, physicochemical properties, and stability of pandan powder. The foamed pandan solution with egg white protein (F‐EW) provided the most stable foam structure and shortened drying time to 6 hr, while the control took 24 hr to dry at the same sample thickness. The F‐EW freeze‐dried pandan powder (FDPP) had the highest hue angle, the highest greenness (a* value), the lowest bulk density, and high solubility. The reaction rate constants for the physicochemical changes in foamed‐freeze‐dried pandan powders were lower than those of the control and the highest color stability was recorded for F‐EW FDPP when stored at high temperature (37°C) for 12 weeks. Egg white at a concentration of 10% w/w is an appropriate foaming agent for producing pandan powder via the F‐FD. Practical applications Natural pandan leaf extract is a commercially available product nowadays both in concentrate and powder form. Functional ingredients are offered to the health‐conscious consumers, such as natural pandan powder with prebiotic. Foam‐mat freeze‐dried pandan powder with various types of foaming agents, such as egg white protein, sodium caseinate, and METHOCEL may be the new alternative technology for the production of functional ingredients which not only use as a natural food colorant and flavor but also as the foaming aid agent in foam‐type food products.

Coating is an effective and economic strategy to increase the functional property of food products. This study investigated the technical feasibility of adding Spirulina platensis to edible polymers, namely carboxymethyl cellulose (CMC) and maltodextrin (MD), in the coating of instant jasmine rice, using a central composite design (CCD). A total of 10 edible coating formulations comprising CMC (10–30% w/v) and MD (1–5% w/v) were evaluated to optimize the most suitable combination of physicochemical properties, textural attributes, and sensory acceptance. The resulting rice fortified with S. platensis and hydrocolloids showed improved textural and functional properties favourable for consumer acceptance. Among these, the optimum (20.0% MD, 1.0% CMC, and 2.0% S. platensis powder) increased the physicochemical properties and decreased textural properties compared with those of uncoated rice. This condition showed phycocyanin content of 1.4 mg/g, chlorophyll a of 181.5 µg/g, total phenolic compound (TPC) of 137.3 µg gallic acid equivalent (GAE)/g, and ferric reducing antioxidant power (FRAP) of 3.8 mg ferrous (Fe2+)/g with overall acceptability of 7.1 (like moderately). It can be stated that masking the colour and flavour of Spirulina with an edible coating could be a healthy alternative to commercial rice and used to fortify cereal products with algae.

An extreme vertices design for a mixture of three components was used to establish the proportions of tapioca flour (50% to 100% w/w), soy flour (0% to 50% w/w), and cane sugar (0% to 10% w/w) mass fractions in a food gel bead system. Thus, nine compositions were prepared and analyzed. The pasting profiles of the mixtures were studied using a Rapid Visco Analyzer. The texture profiles of fresh, chilled, and rehydrated freeze-dried gel beads were studied using a texture analyzer. Increasing the proportion of soy flour in the range of 11.25% to 50.00% w/w decreased the peak viscosity, breakdown, final viscosity, and setback of mixed flour. Tapioca flour in the proportion of 81.25% to 100.00% w/w recorded the lowest hardness of fresh gel beads (92.00 to 283.00 g). Soy flour in the proportion of 11.25% to 50.00% w/w exhibited lower texture profiles (hardness, chewiness, and gumminess) than tapioca flour in gel beads for both chilled and rehydrated freeze-dried gel beads. Significant relationships were found among pasting profiles of the flour mixtures and texture profiles of fresh, chilled, and rehydrated freeze-dried gel beads, implying a functional role for soy flour in food gel beads. In conclusion, soy flour can act as an anti-retrogradation agent for the gel beads both in chilled (stored at 4°C for 7 days) and freeze-dried conditions. A small amount of cane sugar does not affect the inhibition of starch retrogradation in the gel bead system. Keywords: Anti-retrogradation, Food gel bead, Pasting profile, Soy flour, Tapioca flour, Texture profiles