Exploring non-edible parts of pineapples as fat replacers in cake formulations

Non-edible parts of many fruits, such as peel and seeds, are sources of compounds with important nutritional properties. They are also rich in fibres, which gives them the potential to be used as functional ingredients since fibres may be fat replacers in many food formulations. If these parts of fruits are properly transformed into edible forms, there will be potential reuse and recovery of food waste. In the case of pineapple, approximately 70% of the total weight of the fruit is not consumed, being rinds, core, and crown usually discarded. This work aimed to transform pineapples' non-edible parts (rinds and crowns) into powders by freeze-drying with posterior micronization. The objective was to use the powders as fat replacers in a traditional cupcake recipe and assess the texture profile of the baked cakes. Pineapples (Ananas comosus L.) rinds and crowns were removed, cut into small pieces, and freeze-dried. The dried samples were ground in a hammer mill to obtain powders/flours. They were characterized in terms of water activity, water and oil absorption capacity (WAC and OAC), proteins, and total dietary fibre content (on a dry basis, d.b.). These powders were used in a cupcake recipe (control), replacing the fat (butter) with the powders in different proportions: 25, 50, and 75%. Relevant textural parameters such as hardness, cohesiveness, chewiness, and springiness were assessed in the baked cupcakes. Water activity values of rind and crown powders were 0.36±0.02 and 0.49±0.03, respectively. Regarding functional properties, crown flours presented a considerably higher OAC (6.11±0.39 g oil/g d.b.) than the rind (2.45±0.47 g oil/g d.b.); WAC of both flours was similar, averaging 2.30±0.34 g water/g d.b. Protein content was significantly higher in the crown (8.14±0.89 g/100 g d.b.) than in the rind flours (4.43±0.38 g/100 g d.b.). Dietary fibres were mainly insoluble; the crown had 18% and the skin 37%.The texture of cupcakes with 25% of both types of flour was similar to the control. However, as the proportions of the flours increased, texture differed mainly in crown-based recipes, becoming the cakes harder with springiness and adhesiveness decay. These findings suggest that incorporating pineapple waste parts in a traditional cake recipe may serve as healthier ingredients with improved functional properties.info:eu-repo/semantics/publishedVersio

Cortactin Phosphorylated by ERK1/2 Localizes to Sites of Dynamic Actin Regulation and Is Required for Carcinoma Lamellipodia Persistence

Tumor cell motility and invasion is governed by dynamic regulation of the cortical actin cytoskeleton. The actin-binding protein cortactin is commonly upregulated in multiple cancer types and is associated with increased cell migration. Cortactin regulates actin nucleation through the actin related protein (Arp)2/3 complex and stabilizes the cortical actin cytoskeleton. Cortactin is regulated by multiple phosphorylation events, including phosphorylation of S405 and S418 by extracellular regulated kinases (ERK)1/2. ERK1/2 phosphorylation of cortactin has emerged as an important positive regulatory modification, enabling cortactin to bind and activate the Arp2/3 regulator neuronal Wiskott-Aldrich syndrome protein (N-WASp), promoting actin polymerization and enhancing tumor cell movement.In this report we have developed phosphorylation-specific antibodies against phosphorylated cortactin S405 and S418 to analyze the subcellular localization of this cortactin form in tumor cells and patient samples by microscopy. We evaluated the interplay between cortactin S405 and S418 phosphorylation with cortactin tyrosine phosphorylation in regulating cortactin conformational forms by Western blotting. Cortactin is simultaneously phosphorylated at S405/418 and Y421 in tumor cells, and through the use of point mutant constructs we determined that serine and tyrosine phosphorylation events lack any co-dependency. Expression of S405/418 phosphorylation-null constructs impaired carcinoma motility and adhesion, and also inhibited lamellipodia persistence monitored by live cell imaging.Cortactin phosphorylated at S405/418 is localized to sites of dynamic actin assembly in tumor cells. Concurrent phosphorylation of cortactin by ERK1/2 and tyrosine kinases enables cells with the ability to regulate actin dynamics through N-WASp and other effector proteins by synchronizing upstream regulatory pathways, confirming cortactin as an important integration point in actin-based signal transduction. Reduced lamellipodia persistence in cells with S405/418A expression identifies an essential motility-based process reliant on ERK1/2 signaling, providing additional understanding as to how this pathway impacts tumor cell migration