This study examined the effects of rearing, physiological, and processing conditions on the volatile profile of Atlantic salmon. Fish were reared under two different temperature and light conditions, and three harvests were conducted at different time points for male and female fish. Fish were processed to yield fillets with or without skin. Volatiles were analyzed using SIFT-MS headspace analysis. Atlantic salmon reared in cooler temperatures under a 12 h light/dark cycle exhibited significantly lower concentrations of off-odor volatiles compared to those reared in warm conditions under continuous light, suggesting that cooler temperatures with a dark cycle help maintain freshness. A temperature shift from cool to warm further increased volatile accumulation. Longer rearing time resulted in higher volatile concentrations, attributed to greater biochemical products, increased susceptibility to lipid oxidation, protein degradation, and contaminant accumulation from the rearing environment. Males had higher volatile levels at 202 days, while females surpassed males by 242 days, likely due to increased biochemical accumulation associated with reproductive development. Fillets with skin exhibited significantly higher concentration of off-odor volatiles. These findings highlight the role of all studied factors in establishing optimum conditions to minimize spoilage-related volatiles and preserve the freshness of Atlantic salmon, with rearing temperature being the most critical factor.

Atlantic salmon (Salmo salar) is an important dietary source of health-promoting long-chain polyunsaturated fatty acids (PUFAs). As rearing conditions significantly influence fillet quality, this study evaluated the effects of warm and cool rearing temperature and photoperiod regimes on salmon growth, lipid profiles, and antioxidant capacity. Atlantic salmon (210 days old) were reared for 92 days under low temperature (14 °C, 12 h light) or high temperature (21 °C, 24 h light) conditions to simulate relevant seasonal conditions, winter and summer respectively. At day 302, conditions were reversed to create low-to-high (L→H) and high-to-low (H→L) treatments, continuing until day 362. Growth parameters, muscle lipid content, fatty acid profile, and antioxidant activity were measured at 302 and 362 days. Lipid content and fatty acid profile were also measured based on fillet location and fish sex. High rearing temperatures accelerated weight gain and increased total and neutral lipid contents, but elevated saturated fatty acids (SFA) and decreased PUFAs in structural polar lipids. High temperatures also significantly increased antioxidant activity, indicating elevated oxidative stress. Conversely, low temperatures suppressed growth but preserved essential PUFAs and maintained oxidative stability. Following the temperature shift, the H→L group had enriched polar lipids with PUFAs and maintained oxidative stability. On the other hand, L→H group showed lower PUFAs accumulation in polar lipid and enhanced oxidative stress. Total lipid content was higher in the head region, followed by the middle and tail sections of the fillet. However, fatty acid composition remained largely uniform across all three sections of the fillet. There were no significant differences in total lipid content between fish sexes. In conclusion, production efficiency and nutritional quality can be optimized by initially rearing salmon at high temperatures to promote rapid growth, followed by low temperature finishing phase to increase essential PUFA content and maintain oxidative stability.

Atlantic salmon (Salmo salar) is highly perishable during refrigerated storage due to the formation of off-odor volatile compounds that limit shelf life and consumer acceptance. This study investigated the development of off-odor volatiles in Atlantic salmon fillets during refrigerated storage and evaluated how rearing conditions influence storage-induced volatile formation. Salmon reared under warm (20.3 ± 1.95 °C with continuous light) or cool (13.1 ± 0.85 °C with a 12 h light–12 h dark cycle) conditions were harvested, stored at 4 ± 1 °C, and analyzed at 0, 3, 7, 9, and 15 days using selected-ion flow-tube mass spectrometry (SIFT-MS). Refrigerated storage was the primary driver of volatile formation, with lipid-derived aldehydes and alcohols forming early, followed by additional oxidation products as deterioration progressed, and finally, terminal oxidation products. These findings demonstrate distinct temporal pathways of off-odor volatile formation during refrigerated storage, linking early-stage oxidation of polar lipids, mid-stage involvement of neutral lipids, and late-stage accumulation of terminal and microbial products. Protein-derived volatiles exhibited compound-specific behavior, with reactive sulfur- and nitrogen-containing compounds increasing early or mid-storage and microbial metabolites accumulating steadily over time. Environmentally derived off-odor compounds, including geosmin and 2-methylisoborneol, were progressively released during storage as lipid structures degraded. Warm-reared salmon consistently exhibited higher concentrations of lipid- and protein-derived volatiles, indicating greater oxidative and proteolytic susceptibility. Rearing conditions modulate the extent but not the progression of these spoilage mechanisms. This mechanistic understanding provides a basis for targeted strategies to control off-odor volatile compound development and improve refrigerated shelf life and sensory quality of Atlantic salmon.

Tea is one of the most popular and oldest beverages available in many varieties and the use of different flavoring ingredients is becoming more common. The present study aimed to examine tea consumption behavior during the COVID-19 pandemic and analyzed the bioactive compounds of tea flavoring ingredients. At first, a cross-sectional study was carried out with 140 randomly selected participants to determine tea consumption patterns and data was collected through face-to-face interviews. Then 2,2-diphenyl-1-picrylhydrazyl (DPPH) test, the Folin-Ciocalteu technique, and the quercetin method were used to assess antioxidant activity, total phenolic content (TPC), and total flavonoid content (TFC) of tea flavoring ingredients. The study found that 57.86% of the participants increased their tea consumption during the COVID-19 pandemic, whereas 22.80% increased their tea consumption by at least one more cup per day. It was also found that ginger was the most popular (29.5%) among fifteen tea flavoring agents. By analyzing tea flavoring ingredients, the maximum antioxidant activity found in cinnamon was 87%, and lemon leaves had the lowest, which was 60%. On a dry weight basis, the TPC of the tea flavoring components ranged from 36.52 mg GAE/g for cloves to 9.62 mg GAE/g for ginger. The maximum TFC was also found in clove with 13.68 mg QE/g, and moringa was the second highest with 12.26 mg GAE/g. The antioxidant activity of flavoring compounds has a significant correlation (p<0.05) with TPC and TFC. Overall, tea consumption behavior with tea flavoring ingredients increased during the COVID-19 pandemic situation. Tea with flavoring ingredients may be one of the best dietary sources of antioxidants, TPC, and TFC which are important for strengthening the immune system and controlling different physiological and metabolic disorders.

Yellow perch (Perca flavescens) is a high-value aquaculture species, but variation in fillet nutritional composition and off-odor formation can limit product quality. This study evaluated how diets with plant-based antioxidants, rearing environment, use of heat shock, post-harvest processing, and fish weight affected off-odor volatile formation, lipid content, fatty acid profile, antioxidant activity, and vitamin E content in yellow perch fillets. Fish were fed camu camu, wheat flour, mixed starch, or commercial diets for 9 weeks, harvested with or without heat shock, and analyzed after frozen and refrigerated storage or baking. Volatiles were measured by selected-ion flow-tube mass spectrometry, while lipid content, antioxidant activity, vitamin E, and fatty acid profile were evaluated to characterize fillet composition and oxidative stability. Under standard harvest conditions, camu camu– and wheat-fed fish generally showed lower concentrations of lipid oxidation– and protein degradation–derived volatiles than mixed starch- and commercial-fed fish, especially after refrigerated storage or baking. These volatile differences were supported by differences in fillet composition and antioxidant status, with camu camu–fed fish showing the highest lipid content, while camu camu– and wheat-fed fish showed higher antioxidant activity than mixed starch-fed fish. Fatty acid profiling provided additional information on lipid composition and its potential relationship with lipid oxidation–derived off-odor formation. Heat shock increased volatile formation and reduced diet-dependent differences in the volatile profile. Heat shock also increased antioxidant activity across diets, eliminating diet-related differences in antioxidant activity. Rearing water systems and fish weight had limited effects on the volatile profile. These findings show that plant-based antioxidant diets can influence both nutritional quality and off-odor stability in yellow perch, particularly when combined with low-stress harvest and appropriate post-harvest handling.

Off-odor volatiles limit the acceptability of Atlantic salmon. This study investigated the effects of spatial distribution within the fillet, storage conditions, and cooking methods on the volatile profile of salmon and evaluated how pre-harvest rearing conditions, sex, and the presence of skin influence volatile compound formation during storage and cooking. Volatiles were classified as lipid-derived, protein-derived, and environmental contaminants. Spatial distribution within the fillet influenced volatile formation, with the head region exhibiting higher concentrations than the center and tail, reflecting differences in lipid distribution and precursor availability. During storage, fillets stored on ice generally exhibited higher volatile concentrations than samples frozen immediately, particularly for lipid-derived and environmental compounds, consistent with continued biochemical and microbial activity during chilled holding, whereas frozen storage preserved the biochemical state of the fillet. The magnitude of these differences depended on pre-harvest rearing conditions, the presence of skin, and harvest age. Cooking significantly increased volatile concentrations compared to raw fillets, with dry-heat methods, particularly baking, producing the highest levels, while boiling resulted in lower concentrations due to leaching into the cooking medium. Lower volatile formation was generally associated with cool-reared fish, male fillets, and muscle-only samples, while warm-reared, female, and skin-on samples exhibited greater volatile formation or retention, reflecting differences in precursor availability and tissue structure. These findings demonstrate that volatile formation in salmon is governed by the interaction between precursor accumulation during growth, spatial variability within the fillet, and transformation during post-harvest storage and cooking.