Classification of crispness of food materials by deep neural networks.

Crispness is a textural characteristic that influences consumer choices, requiring a comprehensive understanding for product customization. Previous studies employing neural networks focused on acquiring audio through mechanical crushing of crispy samples. This research investigates the representation of crispy sound in time intervals and frequency domains, identifying key parameters to distinguish different foods. Two machine learning architectures, multi-layer perceptron (MLP) and residual neural network (ResNet), were used to analyze mel frequency cepstral coefficients (MFCC) and discrete Fourier transform (DFT) data, respectively. The models achieved over 95% accuracy "in-sample" successfully classifying fried chicken, potato chips, and toast using randomly extracted audio from ASMR videos. The MLP (MFCC) model demonstrated superior robustness compared to ResNet and predicted external inputs, such as freshly toasted bread acquired by a microphone or ASMR audio of toast in milk. In contrast, the ResNet model proved to be more responsive to variations in DFT spectrum and unable to predict the similarity of external audio sources, making it useful for classifying pretrained "in-samples". These findings are useful for classifying crispness among individual food sources. Additionally, the study explores the promising utilization of ASMR audio from Internet platforms to pretrain artificial neural network models, expanding the dataset for investigating the texture of crispy foods.

High-shear wet agglomeration process for enriching cornstarch with curcumin and vitamin D3 co-loaded lyophilized liposomes.

Curcumin and vitamin D3 are bioactive molecules of great importance for the food industry. However, their low stability in several processing conditions hampers their proper incorporation into powdered food formulations. This study proposes the enrichment of a common raw material (cornstarch) with curcumin and vitamin D3 by using high-shear wet agglomeration. The bioactives were initially encapsulated into liposome dispersions and then subjected to lyophilization. The resulting dried vesicles were later incorporated into cornstarch by wet agglomeration using maltodextrin as the binder solution. The phospholipid content and the amount of added liposomes were evaluated to characterize the enriched cornstarch samples. The lyophilized vesicles showed a high retention rate of 99 % for curcumin and vitamin D3, while the enriched cornstarch samples retained above 96 % (curcumin) and 98 % (vitamin D3) after 30 days of controlled storage. All in all, the presence of dried liposomes improved the flowability and delayed retrogradation phenomenon in agglomerated cornstarch. Therefore, this study introduced a novel and reliable method of incorporating hydrophobic and thermosensitive molecules into powdered food formulations by using readily available materials and a straightforward high-shear wet agglomeration process.

Production of a rich-carotenoid colorant from pumpkin peels using oil-in-water emulsion followed by spray drying.

Peels and seeds are byproducts generated during the processing of fruits and vegetables that have been cut off or rejected in the food industry. Pumpkin peels are an example of products that provide valuable nutritional aspects but that have low commercial value. This work aimed at recovering carotenoids from pumpkin peels to produce valuable powders. The pumpkin peel flour was obtained from convective drying and milling processes. Liquid-solid extraction produced the ethanol raw extract with a high carotenoid content. Carotenoid extract and Arabic gum suspensions were mixed in proportions of 1:2, 1:3, or 1:4 w/w. Emulsions produced via Ultra-Turrax (UT) and Ultra-Turrax plus high pressure (UTHP) were evaluated and spray dried. The particles carotenoid concentrations varied from 159.1 to 304.6 µg/g and from 104.3 to 346.2 µg/g for samples primarily produced via UT and UTHP, respectively. UTHP 1:3 particles showed the lowest degradation of carotenoids during 90 days of storage, with a retention index of 79%. The homogenization and spray drying techniques were proven to be suitable steps to preserve the carotenoids recovered from the byproduct studied. Microparticles can be used as a natural dye with potential use in food, pharmaceuticals, and cosmetics.

Encapsulation of wheat germ oil in alginate-gelatinized corn starch beads: Physicochemical properties and tocopherols' stability.

Microencapsulation by production of polymer beads from ionic gelation is a useful method to improve the stability of nutritional compounds. Wheat germ oil is a nutritional source of unsaturated fatty acids and phytonutrients, such as tocopherols (α and ß), phytosterols, carotenoids, and phenolic compounds. This work studied the development of alginate-starch beads over the stability of encapsulated wheat germ oil. The beads contained sodium alginate and gelatinized corn starch in proportions of 2:0, 1:1, 1:2, and 1:4. The addition of small amounts (1:1) of gelatinized starch in the alginate emulsions improved the physicochemical properties and stability during storage. The emulsions had oil droplets with mean sizes ranging from 4.5 to 12.2 µm. The 1:1 samples showed more disperse oil droplets, explained by the molecular interaction between the starch chains and oil. The encapsulation efficiency was higher than 91%, and the beads' mean diameters were between 383.22 and 797.45 µm. The proportion of 1:1 alginate-starch also enhanced the beads' microstructures, avoiding oil oxidation. Six days accelerated stability (65 °C) evidenced higher tocopherols amounts (0.66 mg/g oil) and a lower oxidation (2.52 meq.O2 /kg oil) for the 1:1 samples compared to the remained samples. PRACTICAL APPLICATION: Alginate-gelatinized corn starch beads loaded with wheat germ oil can be used as an ingredient in functional food products for the enrichment of nutrients. The use of starch decreased the oil oxidation and the loss of tocopherols during storage, indicating that the quality of the wheat germ oil will be desirable for longer durations of food storage.

Antifungal activity of nanoemulsions encapsulating oregano (Origanum vulgare) essential oil: in vitro study and application in Minas Padrão cheese

ABSTRACT The objective of this study was to evaluate the antifungal activity of nanoemulsions encapsulating essential oil of oregano (Origanum vulgare), both in vitro and after application on Minas Padrão cheese. Nanodispersions were obtained by the phase inversion temperature method. Cladosporium sp., Fusarium sp., and Penicillium sp. genera were isolated from cheese samples and used to evaluate antifungal activity. Minimal inhibitory concentrations of non-encapsulated and encapsulated oregano essential oil were determined, and they were influenced by the encapsulation of the essential oil depending on the type of fungus. The antifungal activity of the nanoencapsulated oregano essential oil in cheese slices showed no evidence of an effect of the MICs, when applied in the matrix. On the other hand, an influence of contact time of the nanoemulsion with the cheese was observed, due to the increase in water activity. It was concluded that nanoencapsulated oregano essential oil presented an inhibitory effect against the three genera of fungi evaluated. If environmental parameters, such as storage temperature and water activity, were controlled, the inhibitory effect of nanoemulsions of oregano oil could possibly be greatly improved, and they could be presented as a potential alternative for the preservation of Minas Padrão cheese against fungal contamination.

Antifungal activity of nanoemulsions encapsulating oregano (Origanum vulgare) essential oil: in vitro study and application in Minas Padrão cheese.

The objective of this study was to evaluate the antifungal activity of nanoemulsions encapsulating essential oil of oregano (Origanum vulgare), both in vitro and after application on Minas Padrão cheese. Nanodispersions were obtained by the phase inversion temperature method. Cladosporium sp., Fusarium sp., and Penicillium sp. genera were isolated from cheese samples and used to evaluate antifungal activity. Minimal inhibitory concentrations of non-encapsulated and encapsulated oregano essential oil were determined, and they were influenced by the encapsulation of the essential oil depending on the type of fungus. The antifungal activity of the nanoencapsulated oregano essential oil in cheese slices showed no evidence of an effect of the MICs, when applied in the matrix. On the other hand, an influence of contact time of the nanoemulsion with the cheese was observed, due to the increase in water activity. It was concluded that nanoencapsulated oregano essential oil presented an inhibitory effect against the three genera of fungi evaluated. If environmental parameters, such as storage temperature and water activity, were controlled, the inhibitory effect of nanoemulsions of oregano oil could possibly be greatly improved, and they could be presented as a potential alternative for the preservation of Minas Padrão cheese against fungal contamination.

Production of Cornstarch Granules Enriched with Quercetin Liposomes by Aggregation of Particulate Binary Mixtures Using High Shear Process.

Liposomes are colloidal structures capable of encapsulating, protecting, and releasing hydrophobic bioctives, as flavonoids. Quercetin is a flavonoid with high antioxidant activity that provides benefits to health. The wet-agglomeration processes in high-shear equipment are useful to produce granules from binary mixtures, obtaining a powder with homogeneous composition and without segregation or elutriation of fine particles. In this study, the binary mixtures containing microparticles of native cornstarch and nanoparticles of quercetin liposomes were aggregated in high-shear batches, using maltodextrin solution as binder agent. The cornstarch was enriched by agglomeration with 8%, 22%, and 30% (w/w) of quercetin-loaded lyophilized liposomes and the physical properties were evaluated. The moisture of all formulations showed similar values ranging from 4.42% to 4.57%. The values of hygroscopicity (g adsorbed water/100 g of dry matter) indicated the lyophilized liposomes were able to decrease the capacity of the agglomerated cornstarch to absorb water, decreasing the possibility of microbiological contamination. The addition of quercetin-loaded lyophilized liposomes improved the flowability and turned the powder (agglomerated cornstarch) less cohesive. The pasting properties of enriched agglomerated cornstarch decreased the pasting temperature about 10 °C, and the cornstarch agglomerated with 8% (w/w) of quercetin-loaded lyophilized liposomes showed no significance difference in the peak viscosity. Agglomeration of cornstarch with more than 8% (w/w) lyophilized liposomes decreased the tendency of starch to retrograde, which is very interesting for food products which requires low levels of retrogradation of granules for their stability. PRACTICAL APPLICATION: This study is an unprecedent association of 2 technologies, nanoencapsulation and wet agglomeration, here used together to enrich cornstarch with quercetin. The agglomeration process was used to obtain granules of cornstarch, an ingredient extremely used in the food industry, enriched with quercetin-loaded lyophilized liposomes. The goals were both the improvement of the nutritional quality and the increase of the added value of the cornstarch.