Being an important crop, soybean is widely used in the world and plays a vital role in human and animal nutrition. However, it contains several antinutritional factors (ANFs) including soybean agglutinin, soybean protease inhibitors, soybean allergenic proteins, etc., that may result in poor food utilization, decreased growth performance, and even disease. Among these ANFs, soybean allergenic proteins can lead to allergic reactions in human and animals, which has become a public problem all over the world, but our knowledge on it is still inadequate. This paper aims to provide an update on the characteristics, detection or exploration methods, and in vivo research models of soybean allergenic proteins; especially glycinin and β-conglycinin are deeply discussed. Through this review, we may have a better understanding on the advances of research on these two soybean allergenic proteins. Besides, the ingredient processing used to reduce the allergenicity of soybean is also reviewed.

Trans vaccenic acid (TVA; trans-11 18:1) is a positional and geometric isomer of oleic acid and it is the predominant trans isomer found in ruminant fats. TVA can be converted into cis-9, trans-11 conjugated linoleic acid (c9, t11-CLA), a CLA isomer that has many beneficial effects, by stearoyl CoA desaturase 1 (SCD1) in the mammary gland. The health benefits associated with CLA are well documented, but it is unclear whether trans fatty acids (TFAs) from ruminant products have healthy effects. Therefore, the effects of TVA on the proliferation of MCF-7 human breast adenocarcinoma cells and MCF-10A human breast epithelial cells were investigated in the present study. Results showed that TVA inhibited the proliferation of MCF-7 cells but not MCF-10A cells by down-regulating the expression of Bcl-2 as well as procaspase-9. In addition, the suppressive effect of TVA was confirmed in SCD1-depleted MCF-7 cells. Our results suggested that TVA exerts a direct anti-carcinogenic effect on MCF-7 cells. These findings provided a better understanding of the research on the anti-carcinogenic effects of TVA and this may facilitate the manufacture of TVA/c9, t11-CLA fortified ruminant products.

Leucine and isoleucine possess antioxidative and anti‐inflammatory properties. However, their underlying protective mechanisms against oxidative damage remain unknown. Therefore, in this study, the protective mechanism of leucine and isoleucine against H₂O₂‐induced oxidative damage in a bovine mammary epithelial cell lines (MAC‐T cells) were investigated. Briefly, MAC‐T cells exposed or free to H₂O₂ were incubated with different combinations of leucine and isoleucine. The cellular relative proliferation rate and viability, oxidative stress indicators, and inflammatory factors were determined by specific commercial kits. The genes related to barrier functions was measured by real‐time quantitative PCR. The protein expression differences were explored by 4D label‐free quantitative proteomic analyses and validated by parallel reaction monitoring. The results revealed that leucine and isoleucine increased cell proliferation, total antioxidant status (TAS), and the relative mRNA expression of occludin, as well as decreased malondialdehyde (MDA), total oxidant status (TOS)/TAS, IL‐6, IL‐1β, and TOS. When leucine and isoleucine were combined, MDA, TOS/TAS, and the relative mRNA expression levels of claudin‐1, occludin, and zonula occludens‐1 increased when compared to leucine or isoleucine alone. Proteomics analyses revealed that leucine significantly upregulated the propanoate metabolism; valine, leucine, and isoleucine degradation; and thermogenesis pathways, whereas isoleucine significantly upregulated the peroxisome and propanoate metabolism pathways. In conclusion, leucine protected MAC‐T cells from H₂O₂‐induced oxidative stress by generating more ATP to supplement energy demands, and isoleucine improved the deficit in peroxisome transport and promoted acetyl‐CoA production. The findings of this study enhance our understanding of the protective mechanisms of leucine and isoleucine against oxidative damage.

Conjugated linoleic acid (CLA) consists of a group of positional and geometric conjugated isomers of linoleic acid. Since the identification of CLA as a factor that can inhibit mutagenesis and carcinogenesis, thousands of studies have been conducted in the last several decades. Among the many isomers discovered, cis-9, trans-11 CLA is the most intensively studied because of its multiple, isomer-specific effects in humans and animals. This paper provides an overview of the available data on cis-9, trans-11 CLA, including its isomer-specific effects, biosynthesis, in vivo/in vitro research models, quantification, and the factors influencing its content in ruminant products.

Soybean allergy represents a health threat to human and animals. Glycinin and β-conglycinin, the main storage proteins in soybean, have been identified as major food/feed allergens. The present study was conducted to investigate the disappearance of immunoreactive glycinin and β-conglycinin in the digestive processes of piglets. Twelve crossbred piglets, weaned at 21 days of age, were allocated to three dietary treatments in a complete block design, each treatment with four replicates (female/male = 1:1). From day 22–28, the control group was fed diets without leguminous products, while the two treatment groups received diets containing 2.2% purified glycinin or β-conglycinin. All piglets were slaughtered at 29 days of age and digesta was sampled from stomach, middle jejunum, caecum and colon. Results indicated that immunoreactive glycinin and β-conglycinin decreased as the digesta descended down the digestive tract to 0.12% and 0.47%, respectively. Little immunoreactive glycinin was found in the digesta of caecum and colon, while immunoreactive β-conglycinin was detected in the colon. Along the whole digestive tract the disappearance of immunoreactive glycinin was significantly higher than β-conglycinin (p < 0.05).

Glycinin and β-conglycinin have been identified as major food/feed allergens. But effects of glycinin and β-conglycinin on enterocyte migration in piglets are scare. Fifteen weanling (7.06±0.18 kg) General No. 1 barrows, weaned at 28 days, were used. The piglets were randomly allotted to three (A, B and C) treatments with five replicates. The piglets in the A group (control group) were fed diets without ingredients originating from leguminous products, while the piglets in the B or C groups were fed the diets containing purified glycinin or β-conglycinin, which replaced protein in Group A by 4%. All the experimental periods were followed for 7 days. Five-micrometre thick sections of small intestinal tissue were stained with the TUNEL method to assess apoptotic activity, and with Ki-67 immunohistochemistry to assess cellular proliferation. The results indicated that glycinin or β-conglycinin increased proliferative index and apoptotic index in duodenum for piglets (P<0.05).