Identifying volatile compounds in rabbit fish (Siganus fuscescens) tissues and their enzymatic generation

Development and characterization of an aromatic and antioxidant active film based on myofibrillar protein from fish by-products and passion fruit essential oil

This study aimed to develop and characterize an aromatic and antioxidant film based on myofibrillar proteins from the cutting by-product of Scomberomorus brasiliensis filleting on the band saw machine and yellow passion fruit essential oil. Four formulations were produced, varying the concentrations of essential oil of the yellow passion fruit (YPF): C (control, without YPF), O4 (with 0.4 % YPF), O8 (with 0.8 % YPF), and O12 (with 1.2 % YPF). The films were evaluated for mechanical, optical, barrier, structural, thermogravimetric, and degradability properties. The volatile compound profile and antioxidant activity of the films and the oil were also evaluated. The addition of the YPF favored the formation of a structure with less thickness and proportionally reduced the films' water solubility (18.72 to 14.50 %) and water vapor permeability (23.86 × 10-12 to 2.74 × 10-12 g/m s Pa). The films' degradation time in soil was not affected by the incorporation of YPF, with all samples showing 100 % degradation within 15 days. The YPF also efficiently reduced fish odor and incorporated passion fruit aromas in the films. The antioxidant activity of the films increased with the addition of YPF, presenting high values for total phenolics (1.02 to 4.89 mg GAE/g), ABTS (260.21 to 505.52 mMol ET/g), and DPPH (31.83 to 326.21 mMol ET/g). The O12 treatment proved to be the most promising active biodegradable material for making antioxidant packaging for foods sensitive to oxidative reactions due to its stable structure, low solubility, water permeability, desirable aroma, and high antioxidant activity.

Role of lingonberry press cake in producing stable herring protein isolates via pH-shift processing: A dose response study

The effects of cross-processing lingonberry press cake (LPC) (2.5-30 %, dw/dw) with herring co-products on protein yield, oxidative stability and color of pH-shift-produced protein isolates were investigated. Even at 2.5 % LPC, the formation of volatile oxidation-derived aldehydes, including hexanal, (E)-2-hexenal, heptanal, octanal, and 2,4-heptadienal, were prevented during the actual protein isolate production. Adding 10 % LPC successfully prevented formation of all these aldehydes also during eight days ice storage which was explained by the partitioning of phenolics, especially ideain (1.09 mg/g dw) and procyanidin A1 (65.5 mg/g dw), into isolates. Although higher amounts of LPC (20-30 %) further prolonged the oxidation lag phase, it reduced total protein yield, increased the consumption of acid and base, and darkened protein isolates. Therefore, it is recommended to use 10 % LPC when pH-shift-processing sensitive fish raw materials as a route to mitigate lipid oxidation and at the same time promote industrial symbiosis and more circular food production.