Insect protein-based composite film incorporated with E. purpurea-based nanoparticles augmented the storage stability of parmesan cheese.

The objective of this study was to prepare an insect protein-based composite film containing plant extract-based nanoparticles to augment the lipid and microbial stability of cheese. An ultrasonication-mediated green method of synthesis was followed to develop the nanoparticles using E. purpurea flower extract (EP-NPs). The film was developed using locust protein (Loc-Pro) and different levels of EP-NPs [2.0% (T3), 1.5% (T2), 1.0% (T1), and 0.0% (T0)]. It was characterised and evaluated for efficacy using parmesan cheese (Par-Che) as a model system stored for 90 days (4 ± 1 °C). The addition of EP-NPs markedly enhanced the antioxidant and antimicrobial activities of the Loc-Pro-based film as indicated by the results of radical-scavenging activity (ABTS and DPPH), total-flavonoid and total-phenolic contents, ion-reducing potential (FRAP), and inhibitory halos (mm). It also increased (P < 0.05) the density (g/ml), redness (a*), and yellowness (b*) and reduced (P < 0.05) the WVTR (mg/m2t), transparency (%) and lightness (L*) of the Loc-Pro-based film. The film incorporated with EP-NPs showed a marked desirable impact on protein oxidation, lipid stability, microbial quality and antioxidant potential of Par-Che during 90 days of storage. While cheese samples without any film showed mean values of 2.24 mg malondialdehyde/kg, 0.79% oleic acid, 1.22 nm/mg protein, 2.52 log CFU/g and 1.24 log CFU/g on day 90 for TBARS, FFA, total carbonyl content, total plate count and psychrophilic count, samples within T3 films showed significantly lower values of 1.82, 0.67, 0.81, 2.15, and 0.81, respectively. A positive impact of the Loc-Pro-based film was found on the sensory characteristics of Par-Che. Both the Loc-Pro-based film and the digestion simulation improved the radical-scavenging activity and ion-reducing potential of the Par-Che. Our results indicate the potential of Loc-Pro-based film as a means to enhance the storage quality of cheese.

Storage stability of chocolate can be enhanced using locust protein-based film incorporated with E. purpurea flower extract-based nanoparticles.

The study aimed to develop a locust protein (Loct-Prot)-based film to enhance the lipid oxidative and storage stability of chocolate. The E. purpurea flower extract based-nanoparticles (EFNPs) were developed using ultrasonication (500 W and 20 kHz for 10 min) following a green method of synthesis. The EFPNs were incorporated at different levels [T0 (0%), T1 (1.0%), T2 (1.5%), and T3 (2.0%)] to impart bioactive properties to the Loct-Prot-based films which were used for packaging of white chocolate during 90 days trial. The addition of EFPNs increased (P < 0.05) the density of the Loct-Prot-based film which in turn decreased (P < 0.05) the transmittance (%) and WVTR (water vapour transmission rate, mg/mt2) with increasing levels of addition. While brightness (L*) showed a decrease, redness (a*) and yellowness (b*) increased with increasing concentration of EFPNs. No significant (P > 0.05) effect was recorded on other physicomechanical parameters of the film. The addition of EFPNs (P < 0.05) increased the mean values of all the antioxidant and antimicrobial parameters (total flavonoid and phenolic contents, FRAP, DPPH, and ABTS activities, antioxidant release and inhibitory halos) of the film. The presence of Loct-Prot-based film decreased the lipid (TBARS and free fatty acids) and protein (total carbonyl content) oxidation of the chocolate samples during storage. A significant (P < 0.05) increase was observed in the antioxidant properties [FRAP (µM TE/100 g) and DPPH and ABTS activities (% inhibition)] of the chocolate samples after one month and the sensory and microbial qualities towards the end of the storage. The gastrointestinal digestion simulation showed a positive impact on the antioxidant properties of the chocolate. Based on our results, Loct-Prot-based film incorporated with EFPNs can be used to enhance the storage stability of chocolate during storage.

Locust protein hydrolysates have the potential to enhance the storage stability of cheese.

The study evaluated the efficacy of locust protein hydrolysates (LoPHs) to enhance the quality of Cheddar cheese (ChCh) during storage. The locust protein (LoP) was pre-treated [microwave (Mic) or ultrasonication (Ult) or no treatment (Not)] before hydrolysis using alcalase enzyme (3% w/w). The ChCh samples containing LoPHs at the maximum level of 1.5% were evaluated for quality for 3 months (4 ± 1 °C) and subjected to gastrointestinal simulation. Both pre-treatments (Mic and Ult) significantly (P < 0.05) enhanced the antimicrobial and antioxidant activities of the LoPHs (Ult > Mic > Not). The ChCh samples with LoPHs exhibited significantly (P < 0.05) lower means for lipid oxidation (TBARS and free fatty acids), protein oxidation (total-carbonyl content) and microbial counts (psychrophilic, total plate and yeast/moulds) during the storage. A positive effect was found on the sensory quality of ChCh samples after one month of storage. The gastrointestinal simulation improved the antioxidant capacity of the stored ChCh samples. LoPHs can be used as a novel bio-preservative for cheese.