Effect of Heat Processing on IgE Reactivity and Cross‐Reactivity of Tropomyosin and Other Allergens of Asia‐Pacific Mollusc Species: Identification of Novel Sydney Rock Oyster Tropomyosin Sac g 1

1 Scope

Shellfish allergy is an increasing global health priority, frequently affecting adults. Molluscs are an important shellfish group causing food allergy but knowledge of their allergens and cross‐reactivity is limited. Optimal diagnosis of mollusc allergy enabling accurate advice on food avoidance is difficult. Allergens of four frequently ingested Asia‐Pacific molluscs are characterized: Sydney rock oyster (Saccostrea glomerata), blue mussel (Mytilus edulis), saucer scallop (Amusium balloti), and southern calamari (Sepioteuthis australis), examining cross‐reactivity between species and with blue swimmer crab tropomyosin, Por p 1.

2 Methods and results

IgE ELISA showed that cooking increased IgE reactivity of mollusc extracts and basophil activation confirmed biologically relevant IgE reactivity. Immunoblotting demonstrated strong IgE reactivity of several proteins including one corresponding to heat‐stable tropomyosin in all species (37–40 kDa). IgE‐reactive Sydney rock oyster proteins were identified by mass spectrometry, and the novel major oyster tropomyosin allergen was cloned, sequenced, and designated Sac g 1 by the IUIS. Oyster extracts showed highest IgE cross‐reactivity with other molluscs, while mussel cross‐reactivity was weakest. Inhibition immunoblotting demonstrated high cross‐reactivity between tropomyosins of mollusc and crustacean species.

3 Conclusion

These findings inform novel approaches for reliable diagnosis and improved management of mollusc allergy.     

Effect of pretreatments and drying methods on physico‐chemical,sensory characteristics and nutritional value of oyster mushroom

This study was aimed to evaluate the effect of pretreatments and drying methods on the chemical, physico‐chemical, sensory characteristics and nutritional value of oyster mushroom. Chemical analysis of oyster mushroom (OM) showed that the values content were increased by many times when calculated on dry weight basis. Nine treatments of dried mushroom powders (DMP) were prepared using three drying methods (hot air drying, vacuum drying, and sun drying). Also, three pretreatments of each method of drying were used (untreated, blanching by steaming without or with steeped in 0.5% citric acid solution for 30 min).The results and statistical analysis revealed that, sun dried oyster mushroom samples (without pretreatments) were found to be the best. The DMP samples resulting of the sun drying had a highest physico‐chemical properties, sensory evaluation scores, and contents of the mineral elements and amino acids as compared to other pretreatments and drying methods.

Practical applications

Fresh mushrooms have high water content, high enzymatic activity and hence are highly perishable. Thus, in this study nine treatments of dried mushroom powders (DMP) were prepared using three drying methods (hot air drying, vacuum drying and sun drying).Also, three pretreatments of each method of drying were used (untreated, blanching by steaming without or with steeped in citric acid).The DMP samples (untreated) resulting of the sun drying were better than other pretreatments and drying methods regarding quality attributes.     

Macrofungi: A review of cultivation strategies,bioactivity, and application of mushrooms

The production of macrofungi (mushrooms) as well as their economic value have been steadily increasing globally. The use of functional foods, dietary supplements, and traditional medicines derived from macrofungi is increasing as they have numerous health benefits as well as abundant nutrients. Macrofungi are diverse with complex and highly varied growth conditions and bioactive constituents, most macrofungal resources have not yet been fully explored and applicated, leading to an urgent need for appropriate strategies to address the problem. Increasing attention has been paid to the macrofungal cultivation and application, in particular, potential prebiotics. Herein, the present review comprehensively summarizes recent progress in the cultivation, newly identified bioactive constituents, and their effects on gut microbiota as well as the potential ways in which they affect human health. Moreover, the macrofungal food development is discussed to improve food nutritional value and change the quality characteristics of food. Finally, the review addresses consumer safety concerns and the prospective genetic manipulation of macrofungi. We hope that this review can provide a comprehensive research reference for ensuring the safety and efficacy, along with maximizing the value and profitability of macrofungi production.     

超高效液相色谱-串联质谱法测定毒蘑菇中5种强毒性蘑菇毒素含量

目的建立超高效液相色谱-串联质谱法快速检测毒蘑菇中α-鹅膏毒肽、β-鹅膏毒肽、γ-鹅膏毒肽、羧基二羟鬼笔毒肽和二羟鬼笔毒肽5种强毒性蘑菇毒素含量的分析方法。方法样品经甲醇/水(3:7, V:V)混合液超声提取,离心后取上清液过0.22μm微孔滤膜,C18色谱柱分离,超高效液相色谱-串联质谱仪上采用多反应监测正离子模式测定,外标法定量检测。结果蘑菇样本中检测出α-鹅膏毒肽、β-鹅膏毒肽、γ-鹅膏毒肽和羧基二羟鬼笔毒肽4种蘑菇毒素,浓度分别为164、198、33、2208 mg/kg。结论本方法快速简便、准确,可用于因蘑菇毒素引起的食物中毒应急检测。     

肉桂醛熏蒸处理对香菇采后抗氧化能力及多胺的影响

为探究肉桂醛熏蒸处理对香菇采后抗氧化能力和多胺的影响,本研究以‘香菇808’品种为材料,采用不同浓度（0、8、40、80?nmol/L）的肉桂醛（溶剂为体积分数30%乙醇溶液）进行熏蒸处理。通过测定总酚含量、抗坏血酸（ascorbic acid,AsA）含量、抗坏血酸过氧化物酶（ascorbate peroxidase,APX）活力、过氧化氢酶（catalase,CAT）活力、超氧化物歧化酶（superoxide dismutase,SOD）活力、谷胱甘肽还原酶（glutathione reductase,GR）活力、2,2’-联氮-二(3-乙基苯并噻唑-6-磺酸)（2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS）阳离子自由基清除能力、总抗氧化能力及游离态多胺含量指标,评价肉桂醛熏蒸处理的效果。结果表明：在4?℃低温下贮藏30?d后,各浓度肉桂醛熏蒸处理组的香菇抗氧化物酶（APX、CAT、SOD、GR）活力、ABTS阳离子自由基清除能力和总抗氧化能力均高于对照组,其中,40?nmol/L的肉桂醛熏蒸处理的效果最佳,但肉桂醛处理对总酚含量无明显影响。此外,各肉桂醛熏蒸处理组的游离态腐胺含量高于对照组,而游离态亚精胺、游离态精胺含量低于对照组。由此可知,肉桂醛熏蒸处理能够很好地提高香菇的抗氧化性及抗逆性,该研究结果为肉桂醛熏蒸处理在控制果蔬褐变和保鲜方面的应用提供了一定科学依据。     

营养型香菇酒的配制技术

以干香菇、蜂蜜、食用酒精为原料,采用浸泡工艺生产、开发营养型香菇酒。其营养价值高,风味独特,而且具有一定的保健作用。此产品是适合人们保健需要和社会需求的新型饮品。     

Characterisation of moisture migration of shiitake mushroom (Lentinula edodes) during storage and its relationship to quality deterioration

Water is a critical factor influencing the quality of mushrooms. This paper investigated the moisture migration of shiitake mushroom during storage using low-field nuclear magnetic resonance (LF-NMR) and magnetic resonance imaging (MRI) and its relationship to quality deterioration. Three water components assigned as water in different cell compartments of cell wall, cytoplasm and vacuole were observed in shiitake mushroom matrix. As the prolonging of storage time, the right shift of immobilised water and left shift of free water led to the merge of these two peaks at the end of storage. The increase in peak area of water in cytoplasm and decrease in the peak area of water in vacuole indicated evident moisture migration from vacuole to cytoplasm. MRI images showed heterogeneous water distribution in shiitake mushroom, and the water migrated from centre to surface, then evaporated to the environment. Besides, the moisture migration might be related to the weight loss and textural softening of shiitake mushroom.     

Effects of Phosphoryl Oligosaccharides of Calcium (POs-Ca) on Mycelial Growth and Fruiting Body Development of the Edible Mushroom,Pleurotus ostreatus

Phosphoryl oligosaccharides of calcium (POs-Ca) is a calcium salt of phosphoryl maltooligosaccharides made from potato starch. POs-Ca is highly water-soluble and can supply both the calcium ion and acidic oligosaccharides in an aqueous solution. In this study, we investigated the effects of POs-Ca on the mycelial growth and fruiting body yield of Pleurotus ostreatus , which is one of the most widely cultivated edible mushrooms in the world. We cultivated the mushroom using both potato dextrose agar (PDA) medium and sawdust-based medium, with added calcium salts. The addition of POs-Ca into the PDA medium with a calcium concentration of 10 mg increased mycelial growth significantly ( p < 0.05, vs . control). POs-Ca addition to the sawdust-based medium at concentrations of 1.0 to 3.0 g/100 g medium increased the amount of calcium in the fruiting bodies but did not affect the length of the cultivation period or the weight of the fruiting body. The calcium content in the fruiting body increased 12-fold when compared to the control. On the other hand, neither the CaHPO ₄ ･2H ₂ O group nor the CaHPO ₄ ･2H ₂ O with oligosaccharides group showed changes in the calcium content of the fruiting bodies. Our results indicate that the use of POs-Ca in mushroom cultivation allows for the possibility of developing new functional foods like calcium-enriched edible mushrooms. This is the first report describing the effects of POs-Ca on mushroom cultivation.     

食用菌对镉、铅、汞、砷生物富集状况研究进展

食用菌是味鲜、低热量、高蛋白、具有多种生物活性因子的健康食品,野生食用菌更是食物中的珍品。环境镉、铅、汞、砷污染日益严重,通过食物链并经口摄食是人体对环境中有害污染物最主要的暴露途径,所以食品中污染的镉、铅、汞、砷被认为是典型有毒元素。与维管植物相比,大型真菌对生长环境中的金属和类金属等矿质元素具有更强的吸收和富集性能,包括镉、铅、汞、砷。对食用菌中镉、铅、汞、砷的含量水平,在菌体中各部位的分布及其生物富集作用的研究进展进行了概述,特别关注了野生食用蘑菇中镉、铅、汞、砷的研究现状。研究表明通过选择优良品种、改善生产环境、改革栽培技术等,市售人工栽培食用菌在镉、铅、汞、砷的污染问题上有所控制,按照相关标准抽检合格率较高,基本能够保证质量安全。但是野生食用菌种类繁多,生长环境复杂,生长过程可控性差,因此需要进一步加强调研和食用安全风险评价,开发野生食用菌产品质量控制技术,保障消费者的健康。     

食用菌中萜类物质及其生物活性研究进展

近年来,自然资源因其在开发新的生物活性物质方面的巨大潜力而备受关注。食用菌分布广泛,营养物质丰富,具有抗炎、抗肿瘤、抑菌等多种药理作用。萜类物质来源广泛,种类繁多,是天然物质中最多的一类,大量研究表明食用菌中的萜类化合物具有多种生物活性,在医药行业具有重要的开发利用价值。本文主要对食用菌中萜类物质的抗炎、抗肿瘤、抗氧化及抑菌等生物活性进行综述,并对食用菌的开发利用进行展望。