Primary Metabolites and Polyphenols in Rapeseed (Brassica napus L.) Cultivars in China

Defatted meals of 10 rapeseed (Brassica napus L.) varieties were investigated for their total phenolic, phenolic acid (free, esterified, and insoluble-bound forms), and tannin contents. The antioxidant capacities (AC) of methanol extracts from samples were assessed using the 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH•), Folin–Ciocalteu method and ferric reducing antioxidant power (FRAP), and β-carotene–linoleic acid tests. In the fraction of free phenolic acids, sinapic, caffeic, ferulic, syringic, gallic, and p-coumaric acids were identified. In the fraction of esterified phenolic acids, sinapine, sinapoyl glucoside, and disinapoyl gentiobiose were identified. After basic hydrolysis, sinapic, ferulic, cinnamic, and 4-hydroxybenzoic acids were identified, and sinapic acid (SA) constituted 98.3% to 99.6% of the total esterified phenolic acids. Eleven components (sinapic, protocatechuic, p-coumaric, syringic, vanillic, gallic, caffeic, ferulic, salicylic, cinnamic, and 4-hydroxybenzoic acids) in the fraction of insoluble-bound phenolic acids were identified. The AC of the samples correlated with the total phenolic content. Overall, the total phenolics showed a better correlation with AC than the individual phenolic compounds. Moreover, SA, sinapoyl glucoside, and disinapoyl gentiobiose showed a highly significant and strong positive correlation with the AC of rapeseed meals, and the derivatives of cinnamic acid showed a higher correlation with AC than the derivatives of benzoic acid. The change in the canolol content in rapeseeds under microwave irradiation is discussed. The correlation of the canolol formed with SA and its derivatives is discussed.     

Composition,processing, and quality control of whole flaxseed products used to fortify foods

Whole flaxseed (flour) as a good source of omega-3 fatty acid and phytochemicals with excellent nutritional and functional attributes has been used to enrich foods for health promotion and disease prevention. However, several limitations and contemporary challenges still impact the development of whole flaxseed (flour)-enriched products on the global market, such as naturally occurring antinutritional factors and entrapment of nutrients within food matrix. Whole flaxseed (flour) with different existing forms could variably alter the techno-functional performance of food matrix, and ultimately affect the edible qualities of fortified food products. The potential interaction mechanism between the subject and object components in fortified products has not been elucidated yet. Hence, in this paper, the physical structure and component changes of flaxseed (flour) by pretreatments coupled with their potential influences on the edible qualities of multiple fortified food products were summarized and analyzed. In addition, several typical food products, including baked, noodle, and dairy products were preferentially selected to investigate the potential influencing mechanisms of flaxseed (flour) on different substrate components. In particular, the altered balance between water absorption of flaxseed protein/gum polysaccharides and the interruption of gluten network, lipid lubrication, lipid–amylose complexes, syneresis, and so forth, were thoroughly elucidated. The overall impact of incorporating whole flaxseed (flour) on the quality and nutritional attributes of fortified food products, coupled with the possible solutions against negative influences are aimed. This paper could provide useful information for expanding the application of whole flaxseed (flour) based on the optimal edible and nutritional properties of fortified food products.     

微波处理对萌动亚麻籽酚类化合物油相迁移的影响

强化亚麻籽中主要酚类化合物内源性合成和油相迁移对提升亚麻籽油氧化稳定性,最大限度地增加α-亚麻酸生物利用率尤为重要。探究了适度萌动(25℃,24h)联合微波处理(700W,1~5min)对压榨亚麻籽油得率和色泽、脂质构型和结晶熔融性、抗氧化活性和氧化稳定性的影响,并研究了亚麻籽中木酚素和游离酚酸的释放及油相迁移规律。结果表明:单一萌动处理(24h)后亚麻籽油得率降低了7.39%(P<0.05),而进一步微波处理后油脂得率增加了29.31%(P<0.05),这主要归因于微波处理破坏了亚麻籽中油脂体膜结构完整性,导致膜内中性脂质外溢、融合和胞外渗透。微波处理1~5min过程中,亚麻籽油中以LnLnLn构型存在的C18∶3ω3质量分数呈现明显升高趋势,同时总磷脂质量摩尔浓度以及磷脂酰乙醇胺、磷脂酰甘油、磷脂酰肌醇占比显著增加(P<0.05),但未明显影响油脂的结晶行为和熔融特性。与未处理组相比,微波处理5min降低了初级和次级氧化产物水平,显著改善了亚麻籽油的氧化稳定性和抗氧化活性(P<0.05),这主要归因于木酚素大分子及其解聚产物开环异落叶松树脂酚二葡萄糖苷,以及游离酚酸香兰素、香草酸和阿魏酸的油相富集。研究阐释了萌动联合微波预处理对亚麻籽油品质特性的影响,旨在为亚麻籽油提质制取和亚麻籽高值化利用提供理论依据。     

酶法制备人乳替代脂的研究进展

人乳替代脂是一类模拟母乳脂组成的结构脂质,为促进人乳替代脂的绿色高效生产,介绍了母乳脂的甘油三酯组成,对人乳替代脂的酶法制备工艺以及实际应用的研究现状进行了分析、总结和探讨,并展望了未来的研究方向。我国母乳脂中1-油酸-2-棕榈酸-3-亚油酸甘油三酯(OPL)含量最高,其次为1,3-二油酸-2-棕榈酸甘油三酯(OPO)。人乳替代脂的酶法制备工艺包括酯-酯交换法、一步酸解法、醇解-酯化两步法、两步酸解法、酯交换-酸解两步法等。提高酶的催化活性与位置选择性、抑制酰基迁移等是未来酶法制备人乳替代脂的研究方向。     

利用图像分析和深度学习预测油菜籽中总酚含量

目的 建立了一种结合图像分析和深度学习的油菜籽中总酚含量的快速预测方法。方法 利用VGG19网络进行油菜籽图像籽粒特征的提取,通过多个卷积层来学习油菜籽图像的特征,并建立了回归模型用于预测油菜籽的总酚含量。共收集了100种油菜籽样本,将油菜籽样本按照3:1的比例划分为训练集和测试集,利用均方损失函数(MSELoss)和决定系数(r2)评估模型预测准确性。结果 测试集MSELoss=0.0085、r2=0.9914,表明该预测模型具有一定的准确性和实用性。结论 本研究提出了一种快速、准确的评估油菜籽总酚含量的方法,为油菜籽的总酚测定提供一种快速、准确的智能化检测方法。     

Epoxy resin/acrylic composite latexes: reactivity and stability of epoxy groups with carboxyl groups

Epoxy resin (Ep850)/acrylic composite latex was prepared by the miniemulsion polymerization method. Epoxy-functionalized latex made by the miniemulsion polymerization process with Ep850 was compared with that made by the conventional emulsion polymerization process with glycidyl methacrylate (GMA). The reactivity and stability of epoxy groups were investigated in the latexes and films, and quantified by Fourier transform-IR spectrometry. The solvent resistance of films strongly correlated with the residual epoxy groups in latex. The epoxy groups originating from Ep850 in the miniemulsion process were less reactive than those from GMA in the conventional process. Almost all epoxy groups originating from Ep850 in the miniemulsion method were remained even after its polymerization, whereas about 25% of the epoxy groups originating from GMA were lost during the polymerization. When the storage temperature was kept at 50° C, almost all of the epoxy groups in both methods were lost quickly. Most of the epoxy groups in the miniemulsion method were gradually lost at 5° C by cross-linking with carboxyl groups during storage, whereas most of the epoxy groups obtained in the conventional method were gradually lost by hydrolysis. Their differences in reactivity or stability were considered to be due to the difference in hydrophilicity, molecular weight or polymerization method.