Identification of odor volatile compounds and deodorization of Paphia undulata enzymatic hydrolysate

Abstract

Unfavorable fishy odour is an inevitable problem in aquatic products. In the present study, headspace solid-phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) analysis of volatiles from untreated samples and three deodorized samples (under the optimal conditions) of Paphia undulata enzymatic hydrolysate revealed that the compounds contributing to the distinctive odor were 1-octen-3-ol, n-hexanal, n-heptanal, 2,4-heptadienal, and 2,4-decadienal, whereas n-pentanal, n-octanal, n-octanol, benzaldehyde, 2-ethylfuran and 2-pentylfuran were the main contributors to the aromatic flavor. The deodorizing effects of activated carbon (AC) adsorption, yeast extract (YE) masking and tea polyphenol (TP) treatment on a P. undulata enzymatic hydrolysate were investigated using orthogonal experiments with sensory evaluation as the index. The following optimized deodorization conditions were obtained: AC adsorption (35 mg mL −1 , 80℃, 40 min), YE masking (7 mg mL −1 , 45℃, 30 min) and TP treatment (0.4 mg mL −1 , 40℃, 50 min). AC adsorption effectively removed off-flavor volatile aldehydes and ketones. YE masking modified the odor profile by increasing the relative contents of aromatic compounds and decreasing the relative contents of aldehydes and ketones. The TP treatment was not effective in reducing the odor score, but it significantly reduced the relative content of aldehydes while increasing that of alkanes. It is also notable that TP effectively suppressed trimethylamine (TMA) formation in a P. undulate hydrolysate solution for a period of 72 h.

Assessment of the Performance of Electrodialysis in the Removal of the Most Potent Odor-Active Compounds of Herring Milt Hydrolysate: Focus on Ion-Exchange Membrane Fouling and Water Dissociation as Limiting Process Conditions

“…Recently, the valorization of herring milt hydrolysate (HMH) has been much more considered, since it contains high value-added molecules, such as peptides, amino acids, nucleic acids and vitamins, and since it has already proven its relevance regarding metabolic syndrome illnesses [1,8]. However, in spite of these promising aspects, HMH, similarly to other fish hydrolysates, presents the substantial drawback of being associated with unpleasant smells [9]. Since odor is an important criterion for consumer acceptance of a product, there is a real need to overcome this main issue [10].…”

“…Unpleasant odors in fishery products and by-products such as hydrolysates can be, in general, ascribed to the contribution of several compounds [9,11]. Nevertheless, all these compounds present the similarities of being volatile, low-molecular-weight and hydrophobic molecules [12].…”

“…TMA and DMA originate from the breakdown of trimethylamine oxide (TMAO) due to bacterial and enzymatic reactions, respectively, as well as environmental conditions [15]. In addition to nitrogen-containing compounds, other volatile compounds belonging to various chemical groups, such as aldehydes, ketones or alcohols, have already been proven to be associated with off-flavors in fishery materials [9,11,16]. These latter compounds originate from enzymatic reactions, lipid oxidation, microbial actions and environmental or thermic stresses [10].…”

“…Firstly, biological methods are based on the use of microorganisms. However, their action spectrum is often reduced, as they target specific compounds, and their mechanisms remain inaccurate [9,17,18]. Chemical methods involve processes like ozonation or the use of antioxidants.…”

Vacuum evaporation and nitrogen-assisted deodorization affects the antioxidant capacity in the olein fraction of red palm oil and its emulsion products

“…A nitrogen medium is preferable in comparison to steam medium, due to the inert property of the gas and the effectiveness of thermal breakdown of off-taste precursors in the presence of the nitrogen carrier inside the deodorization chamber 8 . Based on various application reports [9][10][11][12] , both methods are capable of deodorizing off-odor compounds in the production of better-tasting and rich-in-antioxidant OFRP.…”