Enzymatic recovery of glycopeptides from different industrial grades edible bird’s nest and its by-products:nutrient,probiotic and antioxidant activities,and physicochemical characteristics

This study was conducted to recover edible bird’s nest(EBN)hydrolysates from different grades of EBN,including the industrial by-products,using enzymatic treatment.The nutrient,physicochemical properties and antioxidant activities of the recovered hydrolysates at different hydrolysis times were evaluated.Results showed that the recovery yield of enzymatic hydrolysis was above 89%for all grades of EBN and the degree of hydrolysis increased over time.Nitrite content(0.321-0.433 mg/L)was below the permissible tolerance level for all samples.Interestingly,the antioxidant activities(DPPH and ABTS scavenging activities and ferric reducing antioxidant powder(FRAP)activity)were significantly higher(P≤0.05)in hydrolysates recovered from EBN by-products(EBNhC and EBNhD)as compared to the high grade EBN hydrolysates(EBNhA and EBNhB).The in-vitro probiotic activity of EBN and its hydrolysates were examined using the probiotic bacterium Lactobacillus plantarum.Evidently,EBN by-products hydrolysate(EBNhD)recorded the highest number of L.plantarum(1.1×1011 CFU/mL),indicating that low grade EBN has the potential as prebiotic material that promotes probiotic activity.This study demonstrated the concept of using EBN by-products hydrolysates for various applications,such as functional ingredients with enhanced bioactivities,to improve its economic value.

A comprehensive review of edible bird nests and swiftlet farming

Edible bird＇s nest （EBN） is currently widely consumed by the Chinese community as tonic food and functional food, which is believed to have many medicinal benefits. Some studies have reported the biochemical compositions of EBN, graded on the basis of colour, nitrate and nitrite contents. Other studies have shown significant biological effects, while ongoing research is in progress to explore potential pharmacological applications. The high demand for EBNs in the global market has forced the local regulatory bodies to monitor swiftlet farming activities, including the EBN cleaning process. Furthermore, numerous techniques have been developed to authenticate EBN; proteomics is likely to be the most promising of these methods. However, there are limited numbers of relevant protein sequences deposited at the database. More research is needed at the molecular level to explore the mechanisms behind the biological functions, such as bone strength improvement, skin rejuvenation, epidermal growth factor activity and cell proliferation.The current and future prospects of EBN and swiftlet farming are critically reviewed in this article.

Characterization of edible bird’s nest by peptide fingerprinting with principal component analysis

OBJECTIVES:Proteins are the major component and play a key role in nutritious and therapeutic functions of edible bird’s nest(EBN);however,limited studies have been conducted on the protein due to difficulties in extraction,isolation as well as identification.This study aimed to provide comprehensive information for the quality evaluation of EBN peptides,which would be a valuable reference for further study on EBN proteins.METHODS:Here,we developed a quality control method using high performance liquid chromatography(HPLC)peptide fingerprints deriving from EBN being digested with simulated gastric fluid.The characteristic peptide peaks were collected and identified by LC-MS/MS.RESULTS:The characteristic peptide peaks,corresponding to the protein fragments of acidic mammalian chitinase-like,lysyl oxidase,and Mucin-5AC-like,were identified and quantified.Interestingly,the principal component analysis indicated that the fingerprints were able to discriminate colour of EBN(white/red)and production sites(cave/house)of White EBN on the same weight basis.As proposed by the model developed in this study,Muc-5AC-like and AMCaselike proteins were the markers with the highest discriminative power.CONCLUSIONS:The overall findings suggest that HPLC peptide fingerprints were able to clearly demonstrate peptide profile differences between genuine and adulterated EBN samples;and classify EBN samples by its color and production site.In addition,the protein identification results suggested that Muc-5AC-like protein was the major protein in EBN.

Preliminary nitrite, nitrate and colour analysis of Malaysian edible bird’s nest

The high nitrite content in edible bird’s nests is a major concern to the local swiftlet industry.It lowers the price of the edible bird’s nests and it brings severe health hazards to consumers and farmers.This research investigated the nitrite and nitrate contents of eight types of local edible bird’s nests by using ion chromatography system and evaluating its colour using the CIE system in L^*a^*b^*parameters.The nitrite content obtained ranged from 5.7 lg/g for the house nests to 843.8 lg/g for the cave nests.The nitrate content for the house and cave nests was 98.2 lg/g and 36,999.4 lg/g,respectively.The cave nests with darker and redder colour had higher nitrite and nitrate contents than the brighter and more yellow house nests.This likely suggests that the nitrite and nitrate contents have correlations with edible bird’s nests colour.Correlations studies suggested that the nitrite content had high correlations with colour parameters,L^*a^*b^*of edible bird’s nests at significant level of P<0.10.These findings suggest that edible bird’s nests’colour may be a useful indicator for measuring nitrite and nitrate contaminations.

Combined enzymatic hydrolysis and herbal extracts fortification to boost in vitro antioxidant activity of edible bird's nest solution

Objective:Edible bird’s nest(EBN)is a popular traditional tonic food in Chinese population for centuries.Malaysia is one of the main EBN suppliers in the world.This study aims to explore the best strategy to boost the antioxidant potential of EBN solution.Methods:In this study,the raw EBN(4%,mass to volume ratio)was initially enzymatic hydrolyzed using papain enzyme to produce EBN hydrolysate(EBNH),then spray-dried into powdered form.Next,4%(mass to volume ratio)of EBNH powder was dissolved in ginger extract(GE),mulberry leaf extract(MLE)and cinnamon twig extract(CTE)to detect the changes of antioxidant activities,respectively.Results:Results obtained suggest that enzymatic hydrolysis significantly reduced the viscosity of 4%EBN solution from(68.12±0.69)m Pa·s to(7.84±0.31)m Pa·s.Besides,the total phenolic content(TPC),total flavonoid content(TFC),total soluble protein,DPPH scavenging activity and ferric reducing antioxidant power(FRAP)were substantially increased following EBN hydrolysis using papain enzyme.In addition,fortification with GE,MLE and CTE had further improved the TPC,TFC,DPPH scavenging activity and FRAP of the EBNH solution.Among the samples,MLE-EBNH solution showed the most superior antioxidant potential at(86.39±1.66)%of DPPH scavenging activity and(19.79±2.96)mmol/L FeSO;of FRAP.Conclusion:This study proved that combined enzymatic hydrolysis and MLE fortification is the best strategy to produce EBN product with prominent in vitro antioxidant potential.This preliminary study provides new insight into the compatibility of EBN with different herbal extracts for future health food production.

Edible Bird's Nest:Food or Medicine?

Edible bird＇s nest （EBN） is derived from the saliva of certain types of swiflets. It is consumed in many parts of the world for its nutritional and medicinal values. Although many claims have been made on the therapeutic and health- promoting effects of EBN, scientific documentations regarding these effects are very limited in published literature. It is not until recently that the biological effects of EBN are being investigated and evidence-based studies are being conducted. Several studies have found that EBN may enhance cell proliferation and differentiation and various beneficial effects have been reported in vitro as well as in vivo. While these studies point towards the potential use of EBN in the treatment or even prevention of several diseases, the mechanisms of action of EBN remain largely unknown and more explorations are needed. This review is one of the very few scientific reviews onEBN which focuses on recent evidence-based discoveries.

燕窝及其提取物对皮肤状态的定性循证研究

目的:系统评价食用燕窝及其提取物对皮肤状态的影响。方法:在中国知网、万方、中国生物医学文献服务系统、PubMed和Embase数据库中检索自2012年1月—2022年9月国内外发表的相关文献,并根据纳入排除标准对文献进行筛选,参照世界卫生组织(WHO)推荐的证据评价方法和标准、SYRCLE动物实验风险评估工具对人群研究、动物实验进行综合评价,并根据体外实验探讨可能作用机制。结果:共纳入10项研究,其中3篇为随机对照试验、3篇为动物实验、4篇为体外实验。综合分析结果显示,食用燕窝有助于提高皮肤含水量,减轻皮肤光老化和炎症水平,其提取物有助于促进角质形成细胞的增殖以及皮肤美白等。结论:目前研究结果提示,食用燕窝及其提取物有助于改善皮肤在紫外线暴露下的损伤,还能抑制黑色素的产生,促进皮肤美白,有助于促进表皮角质形成细胞的增殖,减少皮肤损伤。因此,适当摄入燕窝有助于皮肤状态的改善。但目前人群研究较少,还有待进一步的研究验证。

A sustainable way of agricultural livelihood:edible bird’s nests in Indonesia

Edible birds’nests(EBNs)have traditionally been produced in Southeast Asia.Indonesian farmers construct buildings for swiftlets and harvest their nests.EBN farming does not directly degrade forest resources and is therefore considered a sustainable means of production,whereas the expansion of other agricultural activities often relies on the degradation of natural resources.This study examines the relationship between natural resources and agricultural livelihoods,focusing on Indonesian EBN farmers.Using survey data that we collected in 2017,combined with satellite information on the extent of the forest in Central Kalimantan,Indonesia,we measured production efficiency and identified the natural and social factors that enhance production performance.The results show that a forest extent ranging between 2,000 and 6,000 meters from nesting building is positively associated with the production efficiency of EBN farming,perhaps because extensive forest could help swiftlets to collect food and build nests.Conversely,while EBN farming is a sustainable and profitable option,the initial costs of constructing buildings to house swiftlets may deter farmers from participating in the process.

原料蒸制预处理对即食燕窝品质的影响研究

以燕盏和纯净燕为研究对象,探究蒸制预处理对燕窝微生物安全、加工特性和成品品质的影响。设置蒸制时间梯度为15 s、30 s、1 min、4 min、7 min和10 min,测定燕窝菌落总数、涨发倍数、硬条占比、固形物含量和质构变化,采用低场核磁考察燕窝内部水分存在形式,在扫描电镜下观察正常燕条和硬燕条的微观结构。结果表明,蒸制预处理能有效降低燕窝干料中的微生物数量,同时导致涨发倍数降低和硬条占比提高。蒸制时间控制在10 min以内,燕盏的固形物含量维持在90%以上,而超过4 min后纯净燕的固形物含量显著降低(P<0.05)。蒸制时间延长,燕盏的硬度、胶黏性显著提高(P<0.05),黏度先上升后下降;纯净燕硬度、胶黏性同样提高,但黏性呈下降趋势。蒸制处理引起燕窝炖煮后水与组分的结合程度增加。扫描电镜结果显示,过长时间的蒸制处理导致燕条表面和内部的多孔结构破坏和完整度降低是燕窝吸水性、持水性和感官品质下降的原因。总之,适当的蒸制预处理改善即食燕窝的品质,然而针对不同的燕窝原料,需要控制不同的蒸制强度。

体视镜在燕窝鉴别中的应用

目的:研究体视镜在燕窝鉴别中的可行性。方法:观察白燕碎、血燕盏、银耳碎及涂胶白燕盏在体视镜下的特征区别。结果:体视镜可区分燕窝碎与伪品银耳,主要区别在于两者的透明度及表面纹理:体视镜还可根据燕窝的表面纹理及绒羽的存在状态识别出涂胶燕窝。讨论:体视镜可用于燕窝的鉴别,尤适于在研究初期对大量商品作普查时使用。

燕窝对正常小鼠肠道菌群的影响

观察燕窝对正常小鼠肠道菌群的影响,评价其对肠道微生态调节的作用。昆明种小鼠40只,分成4组,即正常对照组,燕窝高、中、低剂量组。灌胃给药28d后,选用厌氧及需氧菌选择性培养基测定盲肠内容物标本中代表性菌种肠杆菌、肠球菌、产气荚膜梭菌、拟杆菌、双歧杆菌和乳酸杆菌数量。与空白对照组相比,燕窝各剂量组小鼠肠道肠杆菌含量显著降低(P<0.01或P<0.05);燕窝高剂量组产气荚膜梭菌含量显著下降(P<0.05);燕窝中、高剂量组肠球菌含量显著下降(P<0.05或P<0.01);燕窝中、高剂量组小鼠拟杆菌含量显著增加(P<0.05);燕窝高剂量组双歧杆菌、乳酸杆菌含量显著上升(P<0.05)。说明燕窝可通过扶植肠道有益菌、抑制有害菌来调节小鼠肠道菌群。

燕窝中唾液酸的含量测定

目的:建立燕窝中N-乙酰神经氨酸的分离分析方法。方法:燕窝中的N-乙酰神经氨酸在0.5mol·L^(-1)硫酸氢钠溶液中水解30min后,以邻苯二氨盐酸盐(10mg·mL^(-1))为衍生化试剂,80℃水浴中衍生40min。采用Alltima C_(18)柱(250mm×4.6mm,5μm);流动相为1.0%四氢呋喃水溶液(含0.2%磷酸)-乙腈(92:8);流速为1.0mL·min^(-1);柱温:35℃;紫外检测波长230nm。结果:N-乙酰神经氨酸在40～320μg·mL^(-1)范围内线性良好;平均回收率分别为96.82%;RSD为1.2%(n =6)。结论:本方法具有灵敏度高、重复性好等特点,可准确测定燕窝中N-乙酰神经氨酸的含量,同时也为真假燕窝的鉴别提供了一种行之有效的方法。

燕窝蛋白质样品制备方法的比较及其双向电泳分析

燕窝水提及丙酮沉淀蛋白质经液相等电聚焦电泳纯化后,再经双向电泳分离获得了质量较佳的2-DE图谱,由此可见液相等电聚焦电泳是对燕窝蛋白质进行纯化的有效手段。对纯化后的2个白燕窝和1个血燕窝水提及丙酮沉淀蛋白质进行了双向电泳分析,结果显示两种方法制备蛋白质获得的2-DE图谱非常相似。燕窝水提蛋白质经丙酮沉淀制备样品时间较透析、冻干所需的时间短,这对于成分复杂蛋白质提取率较低的血燕窝则更为适用。

液相等电聚焦电泳纯化燕窝蛋白质

以市售燕窝为材料,采用MicroRotofor系统进行液相等电聚焦电泳(liquid-phase isoelectric focusing,LIEF)纯化燕窝蛋白质,等电聚焦电泳后对收集到10个小室的样品进行SDS凝胶电泳分析。结果显示,燕窝蛋白质提取液中的一些胶状物聚集在聚焦槽酸端第1～4样品室,第9、10样品室杂质也较多,合并第5～8样品室的样品,即得纯化后的燕窝蛋白用于后续双向电泳分析。液相等电聚焦电泳预分离纯化技术结合双向电泳技术,对4个燕窝蛋白质进行较好的分离,在2-DE胶上检测到约30～60个蛋白质点。由此可见,液相等电聚焦电泳预分离技术是燕窝蛋白质进行2-DE分离前的重要纯化手段。

液相色谱-串联质谱法测定冰糖燕窝中的唾液酸

建立液相色谱-质谱串联法(HPLC-MS)测定冰糖燕窝中唾液酸的含量。采用Inertsil ODS-SP(5μm,4.6mm×250mm)色谱柱,以甲醇-水(50∶50)为流动相洗脱,流速0.8m L/min,柱温35℃,在电喷雾离子源负离子源选择离子模式测定。唾液酸在测定的浓度范围内线性关系良好(r>0.999);方法回收率为97.93%,RSD为1.01%。本方法简便、准确、灵敏,可为冰糖燕窝制品的质量控制提供可靠的依据。

不同加工工艺对燕窝产品唾液酸含量的影响

本文以毛燕为原料,研究浸泡、挑拣、高温灭菌等工艺流程处理后燕窝唾液酸含量的变化。采用LC-MS/MS检测分析燕窝中唾液酸种类,此外,测定了不同加工条件下燕窝产品唾液酸含量并分析加工条件对唾液酸含量的影响,进一步分析了唾液酸热稳定性。结果表明:燕窝中唾液酸仅由N-乙酰基神经氨酸(Neu5Ac)组成,经不同工艺条件处理后,Neu5Ac保留率均可高达95%以上,且Neu5Ac热稳定性好,不同情况下Neu5Ac含量无明显差异。说明燕窝经过上述加工处理后不会造成燕窝酸的大量流失,并且其受工艺条件变化影响小,燕窝加工产品可以很好地保存燕窝的营养价值,从而稳定发挥其营养功效,具有很高的消费价值。

燕窝回乡记

通过燕窝“回乡”的经历,借用拟人的手法,以第一人称的方式讲述了燕窝的主要成分以及相应的功效和危害、燕窝中唾液酸的制备方法、燕窝的掺假及真伪辨别,让读者以生动活泼的方式了解燕窝。

固相微萃取/气相色谱-质谱联用技术测定燕窝中挥发性成分

该文以印尼产的燕窝为材料,使用固相微萃取(SPME)技术萃取燕窝中挥发性成分并以气相色谱-质谱(GC-MS)联用仪进行测定。考察了萃取头类型、萃取温度、萃取时间和解吸时间对固相微萃取(SPME)在燕窝挥发性成分测定中的影响。结果表明:以65μm聚二甲基硅氧烷/二乙烯基苯(PDMS/DVB)萃取头、在60℃下萃取60 min,解吸2 min的条件下,SPME/GC-MS技术可检出燕窝中挥发性成分醇、烃、醛、酯、醚类等化合物共82种。该方法具有操作简便、快速、重复性好和灵敏度高的特点,适用于燕窝中挥发性成分的测定。

固相萃取-高效液相色谱-串联质谱法同时测定燕窝中45种激素及其水平调查

建立了固相萃取-高效液相色谱-串联质谱(SPE-HPLC-MS/MS)同时测定食用燕窝中皮质激素、雌激素、雄激素及孕激素等5类45种激素的多残留分析方法。采用乙腈-乙酸乙酯(1∶1,v/v)超声辅助提取、亲水亲脂平衡固相萃取柱净化,甲醇洗脱。分别在正、负电喷雾电离源、多反应监测模式下检测45种激素。正离子模式下的流动相为乙腈-0.1%甲酸水溶液,负离子模式下的流动相为乙腈-水,色谱柱为Phenomenex Kinetex C_(18)柱(100 mm×2.1 mm,2.6μm)。在优化条件下,45种激素在0.20~20.0μg/L范围内线性关系良好,相关系数(R^(2))≥0.9990,方法的检出限(LOD)为0.04~0.70μg/kg,定量限(LOQ)为0.16~2.00μg/kg。按三水平(2.0、4.0、20.0μg/kg)进行加标回收试验,氟米龙、布地奈德、醛固酮、醋酸氟轻松、炔雌醇的回收率为40.2%~63.6%,可对这5种激素进行定性分析,其余40种激素的平均加标回收率为72.2%~112.3%,相对标准偏差(RSD)为2.5%~11.6%,该方法可对40种激素进行准确定性定量,精密度好,灵敏度高,简便、快速。从2017~2021年,通过研究建立的方法对来自马来西亚、印度尼西亚、泰国和越南等国家的1021个燕窝样品进行监测,仅勃地酮、雄烯二酮、孕酮有检出(大于检出限),其他激素均小于检出限。孕酮检出率为100%,勃地酮、雄烯二酮检出率分别为79%和89%,3种激素含量范围分别为0.097~3.58、0~0.096和0~1.77μg/kg。与同为动物源性食品的鸡蛋、纯牛奶、乳制品相比,所有测定的鸡蛋样品中均检出雄烯二酮,含量比其他3类产品略高;勃地酮在4类产品中的含量差别不大,均为微量;孕酮含量在鸡蛋中最高,其次是纯牛奶,燕窝中含量最低。研究结果表明,食用燕窝带入的激素种类少,含量低,对健康影响小。

燕窝真伪鉴别研究进展

燕窝是一种享有盛名的优质功能食品,由于供不应求,导致价格昂贵。受经济利益的驱使,市场上燕窝的质量参差不齐,假冒伪劣现象严重。为了实现对燕窝质量的有效监督,燕窝真伪鉴别检测技术处于不断的发展与创新中。该文综述了燕窝掺假的鉴别方法,包括理化鉴别、色谱与光谱鉴别、分子生物学鉴别及其他鉴别方法,为后续燕窝真伪鉴别研究提供参考。