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In this study, the effect of temperature fluctuations on the taste quality of tilapia fillets during frozen storage was investigated. Major temperature-responsive factors included free amino acids (FAAs) and flavor nucleotides in fish fillets, which were identified using multidimensional infrared spectroscopy (MM-IR). The main FAA in tilapia fillets is a sweet amino acid (glycine). Compared with the control group, the umami FAAs and sweetness FAAs were significantly increased, and the total FAAs content increased to 1.30 times after the ninth fluctuation, reaching the highest level (611.16 ± 73.60 mg/100 g). Considering the equivalent umami intensity values, adenosine monophosphate and inosine monophosphate were retained during the first and second temperature fluctuations. In addition, the content of Na

Phospholipid (PL) have favorable emulsification ability. The simultaneous application of PL and protein is one of the research hotspots. In this work, the impact of egg yolk PL (EPL), soyabean PL (SPL) and their concentrations on the fish oil-loaded PL/gelatin (GTN)-stabilized emulsions were studied. The results suggested that SPL/GTN-stabilized emulsions comprised bimodal of droplets, and monomodal was observed in EPL/GTN, and GTN-stabilized emulsions. The related droplet sizes were as follows: 1.5% EPL/GTN < 1.0% EPL/GTN < 0.5% EPL/GTN < 2.0% GTN < 0.5% SPL/GTN < 1.0% SPL/GTN < 1.5% SPL/GTN.; and (4) Conclusion: The concentration of PL had significant effect on the droplet size and emulsion stability of the emulsions. The 1.0% SPL/GTN-stabilized emulsions demonstrated the optimal stability and droplet size when stored at room temperature for 15 days than emulsion contained PL. The addition of PL inhibited lipid oxidation and increased the rate of fatty acid release in vitro digestion. This work illustrated that PL/GTN-stabilized emulsions could potentially be a targeted delivery medium for nutrients or drugs.

The effects of hot air drying (HAD), vacuum hot air drying (VHAD), microwave drying (MWD), and vacuum freeze drying (VFD) on free amino acids (FAAs) and flavor nucleotides in scallop adductor muscle (SAM) were studied. The liquid chromatography and multidimensional infrared spectroscopy (MM-IR) were used. Compared with fresh SAM, the main FAAs were glycine, alanine, arginine, and glutamic acid in dried SAM. The total FAAs content in VFD group was 1.40-1.90 times of the other group. The umami taste nucleotides (IMP and AMP) content in the VFD and MWD groups was significantly higher than that in HAD and VHAD groups. Equivalent umami concentrations were found: VFD MWD VHAD HAD. MM-IR analysis was an efficient method for identifying taste components. The results revealed FAAs and flavor nucleotides and the mutual adjustment of compounds were related to drying method, and VFD was preferred for taste substance retention in scallops.

Perturbed lipid metabolism leads to ectopic lipid accumulation in tissues, such as the liver, thereby causing nonalcoholic fatty liver disease (NAFLD) and negatively influencing circulating lipid profile-inducing dyslipidemia. Phospholipids (PLs) with special biological activity are used to treat chronic diseases such as cardiovascular and cerebrovascular disease. PLs derived from egg yolk and soya bean have significant antioxidant and lipid-lowering abilities. This study examined the therapeutic effects of them on hyperlipidemia using a high-fructose-fed rat model, lipid metabolism and anti-inflammatory effects were also analyzed. The results showed that both egg yolk and soya bean phospholipids (EPLs and SPLs) reduced liver weight, hepatic TG, and MDA content as well as serum ALT, AST, TBA, and CRP levels (p &lt, 0.05). The PLs also showed hypolipidemic and anti-inflammatory effects. EPLs and SPLs could inhibit the accumulation of hepatic fatty acids C18:1N9C, C18:0, and C22:6NS of rats fed a high-fat-and-sucrose diet. The intake of EPLs could significantly increase acetylcholine content in the blood and brain tissue. Histological examination showed that PLs intake could ameliorate the damage to liver tissue. This study suggested that EPLs and SPLs had a certain capacity of hypolipidemic and liver protection, and the therapeutic benefits of EPLs tended to be more effective than that of soybean phospholipids.

We investigated the potential for exploiting Stevia rebaudiana stem (SRS) waste as a source of edible plant-based antioxidants finding for the first time that the hot water extract of SRS had significantly higher antioxidant activity against fish oil oxidation than that of the leaf, despite SRS extract having lower total phenolic content, DPPH radical scavenging activity and ORAC values. To locate the major antioxidant ingredients, SRS extract was fractionated using liquid chromatography. Five phenolic compounds (primary antioxidant components in activity-containing fractions) were identified by NMR and HR-ESI-MS: vanillic acid 4-O-β-d-glucopyranoside (1), protocatechuic acid (2), caffeic acid (3), chlorogenic acid (4) and cryptochlorogenic acid (5). Further analysis showed that, among compounds 2-5, protocatechuic acid had the highest capacity to inhibit peroxides formation, but exhibited the lowest antioxidant activities in DPPH and ORAC assays. These results indicate that SRS waste can be used as strong natural antioxidant materials in the food industry.

ステビア茎粗抽出物は強い抗酸化活性を示した.その活性は抗酸化指数で葉に比べ5倍程度高く,現在ほとんど利用されていない茎の新たな利用価値を提示した.ステビア抽出末はマイワシ油およびリノール酸に対して100ppmの添加で抗酸化効果を発現した.その効果は同濃度のBHT,α-Tocに匹敵する強さを示した.ステビア抽出末はα-Tocおよびクエン酸を併用することにより抗酸化効果が増強された.ステビア抽出末の抗酸化有効成分は主として透析外液(分画分子量500)に存在した.外液濃縮物を逆相カラムクロマトグラフィー.薄層クロマトグラフィーで分画し,複数の有効画分を認めた.その多くは,ポリフェノール化合物であったが,最も強い効果を示した成分にはカリウムが高濃度で存在した.

ステビア抽出末に強い抗酸化活性を認め,その活性の最も強い画分には高濃度のカリウムの存在が認められたことから,カリウム塩を含む9種類の無機塩の抗酸化効果を調べた.その結果,K2CO3,KHCO3,Na3PO4,Na2CO3およびKClにリノール酸に対する抗酸化効果を認めた.NaCl,CaCl2,MgCl2およびMgSO4には抗酸化効果は認められなかった.K2CO3は60ppm(カリウム濃度として)以上の濃度で抗酸化効果を示し,最も強力であった.α-Tocと併用することでその効果は向上したが,クエン酸とでは向上は認められなかった.ステビア抽出末の抗酸化作用機構について,フリーラジカル捕捉効果,スーパーオキシド捕捉効果および金属キレート作用について調べた.ステビア抽出末の抗酸化効果は主としてフリーラジカルの捕捉効果に因るもので,スーパーオキシドの消去能も補足的に関わっているものと考えられた.

1. 魚油の酸化により発生する臭いを熱線型半導体式ガスセンサーであるニオイセンサーにより測定する条件について検討した.2. 今回設定した測定条件によればニオイセンサーにより求めたニオイ濃度値は魚油の酸化程度の指標として用いることができることを明らかにした.3. 本法が抗酸化剤の効果の評価の際に応用できることを示した.