不同成熟期白梨品种糖酸质量分数及风味评价

以成熟期不同的9个白梨品种为材料,通过测定果实糖和有机酸组分,研究早熟、中熟与晚熟品种间糖酸组分及质量分数的差异,在此基础上比较各品种间的果实风味指数。研究结果表明:成熟期不同的梨品种间果实糖酸组分及质量分数存在较大差异,并且在总糖或总酸质量分数差异不显著的条件下,不同品种间果糖、葡萄糖和蔗糖等糖组分质量分数,苹果酸、柠檬酸和琥珀酸等有机酸组分质量分数存在显著差异;与糖酸比相比,果实风味指数更能反映果实的真实风味。从果实风味指数角度来考虑,早熟品种中‘雪青’风味最佳,中熟品种‘黄冠’最佳,晚熟品种中则以‘雪花梨’最佳。     

薄皮甜瓜后熟过程中香气成分的动态分析

采用SPME与GC-MS联用技术,测定哈甜-2号薄皮甜瓜后熟过程中7个时期果实香气物质的种类及其相对含量。试验共检测到香气物质77种,香气物质的种类随果实的后熟而减少,且含量均有不同变化。其中酯类物质达40种,占香气成分峰面积的90 %以上,共有12种特征性酯类,包括乙酸甲酯、乙酸乙酯、乙酸丙酯、乙酸异丁酯、丁酸乙酯、乙酸丁酯、乙酸-2-甲基-1-丁酯、3-羟丙基硫代乙酸酯、乙酸己酯、2,3-丁二醇二乙酸酯、异丙氧基乙酸乙酯和乙酸苄基酯。酯类物质是果实香气的重要组成成分,其中乙酸乙酯与2,3-丁二醇二乙酸酯相对含量的变化较为明显。     

不同工艺处理对决明茶饮风味及黄酮含量的影响

为了筛选出决明茶的最佳炮制工艺,为决明茶的科学炮制提供参考。通过利用恒温电热鼓风干燥箱处理决明子,探讨不同温度和时间的工艺处理对决明子茶饮风味及水浸黄酮含量的影响。经170℃处理759、0 min的决明子,冲泡前香味较浓。未粉碎冲泡,3 min即呈现棕色和深棕色,口感香,10 min后品尝口感更香。经160℃处理759、01、05 min和170℃处理607、59、0 min的样品,粉碎后冲泡立即呈现浓咖啡色,且香气浓郁。经160℃处理105 min、170℃处理751、05 min和180℃处理75 min的决明子,未粉碎冲泡时,黄酮含量分别为1.108 81、.138 11、.012 61、.544 0 mg/g。经160℃处理607、59、0 min和170℃处理901、05 min和180℃处理105 min的决明子,粉碎冲泡时,黄酮含量分别为1.795 12、.029 5、1.987 71、.544 01、.598 5、1.736 6 mg/g。使用未粉碎的决明子时,170℃处理75 min的工艺为最佳,使用粉碎决明时,160℃处理759、0 min的工艺为最佳。     

Comparison of textural and compositional attributes of green and white asparagus produced under commercial conditions

Maize ogi was supplemented with 10 and 20% toasted and untoasted okra meals. Yields and chemical composition of ogi, and okra meal, and ogi substituted with okra meal were determined. Brabender paste properties of ogi and ogi substituted with okra meal mixtures were determined. Sensory acceptability of cooked colored and flavored ogi pastes was determined. Yields of ogi were 67.8% while yields of the toasted and untoasted okra seed meals were 35.1 and 39.9% respectively. Supplementing ogi with okra meal increased protein,ash, oil and fiber contents, but reduced ogi viscosity. Addition of yellow color did not significantly improve the color rating, but addition of vanilla flavor improved the flavor of ogi supplemented with untoasted okra meal significantly.     

食品风味物质分离分析技术进展

简述了食品中风味物质的特点,综述了顶空、固相微萃取、同时蒸馏萃取、超临界CO2萃取、气质联用、液质联用、气相嗅觉测量和电子鼻常用的几种分离分析食品中风味物质方法的研究进展。     

Respiration and quality responses of sweet cherry to different atmospheres during cold storage and shipping

Most sweet cherries produced in the US Pacific Northwest and shipped to distant markets are often in storage and transit for over 3 weeks. The objectives of this research were to study the effects of sweet cherry storage O₂ and CO₂ concentrations on the respiratory physiology and the efficacy of modified atmosphere packaging (MAP) on extending shelf life. Oxygen depletion and CO₂ formation by ‘Bing’ and ‘Sweetheart’ cherry fruit were measured. While respiration rate was inhibited linearly by reduced O₂ concentration from 21% to 3–4% at 20 °C, it was affected very little from 21% to ∼10% but declined logarithmically from ∼10% to ∼1% at 0 °C. Estimated fermentation induction points determined by a specific increased respiratory quotient were less than 1% and 3–4% O₂ for both cultivars at 0 and 20 °C, respectively. ‘Bing’ and ‘Sweetheart’ cherry fruits were packaged (∼8 kg/box) in 5 different commercial MAP box liners and a standard macro-perforated polyethylene box liner (as control) and stored at 0 °C for 6 weeks. MAP liners that equilibrated with atmospheres of 1.8–8.0% O₂ + 7.3–10.3% CO₂ reduced fruit respiration rate, maintained higher titratable acidity (TA) and flavor compared to control fruit after 4 and 6 weeks of cold storage. In contrast, MAP liners that equilibrated with atmospheres of 9.9–14.4% O₂ + 5.7–12.9% CO₂ had little effect on inhibiting respiration rate and TA loss and maintaining flavor during cold storage. All five MAP liners maintained higher fruit firmness (FF) compared to control fruit after 6 weeks of cold storage. In conclusion, storage atmospheres of 1.8–14.4% O₂ + 5.7–12.9% CO₂ generated by commercial MAP, maintained higher FF, but only the MAP with lower O₂ permeability (i.e., equilibrated at 1.8–8.0% O₂) maintained flavor of sweet cherries compared to the standard macro-perforated liners at 0 °C. MAP with appropriate gas permeability (i.e., equilibrated at 5–8% O₂ at 0 °C) may be suitable for commercial application to maintain flavor without damaging the fruit through fermentation, even if temperature fluctuations, common in commercial storage and shipping, do occur.     

肥料种类对不同采收期‘黄金梨’糖酸含量和风味的影响

【目的】为优化肥料类型组合和用量、确定果实品质最佳的采收期,【方法】以5年生‘黄金梨’为材料,应用田间试验方法,研究了5种肥料类型对不同采收期‘黄金梨’果实糖、有机酸组分含量和风味的影响。【结果】结果表明,施用堆肥+叶片喷施氨基酸肥或腐熟动物废弃料可显著提高果实总糖、蔗糖、果糖和葡萄糖含量,降低总酸及苹果酸、酒石酸含量,而施用鸡粪+草炭或堆肥+生物菌肥与单施农家堆肥相比效果不明显。采样期间(9月14日—10月10日),不同肥料类型处理‘黄金梨’果实总糖和果糖、蔗糖、葡萄糖含量及风味指数均先增加后降低,总酸和苹果酸、酒石酸含量则先降低后增加,9月28日采样时总糖及各糖分含量最高,总酸及有机酸组分含量最低,糖酸比和风味指数最大,且以堆肥+叶片喷施氨基酸肥或腐熟动物废弃料两个处理效果最好。【结论】综合分析,‘黄金梨’施用堆肥+叶片喷施氨基酸肥或腐熟动物废弃料有利于提高果实内在品质和风味;9月28日左右是北京地区黄金梨果实采收的最适时期。     

程度相似度评价烟用香精质量

采用气相色谱/质谱法（GC/MS）建立烟用香精指纹图谱,计算并比较12种烟用香精6批次样品、稀释品和掺兑品的夹角余弦、相关系数和程度相似度。结果表明,程度相似度算法可较好的反映样品间的质量差异。     

Analysis of Mount Atlas mastic smoke: A potential food preservative

Pistacia terebinthus L. smoke has been used traditionally in Iran as disinfectant and air purifier. Smoke was collected by a simple method, and the chemical constituents and antimicrobial activity of the smoke were analyzed. The chemical constituents of the smoke were α-pinene (65.1%), limonene (11.5%) and allo-ocimene (2.8%). The non polar phase of smoke noticeably inhibited the growth of different microorganisms. MIC test shows that non polar fraction of smoke can inhibit the growth of some bacteria. The results indicating that the properties of the smoke as a flavoring and preservative agent could be a potential subject for future studies.     

气质联用检测沉香燃烟粒相物中的挥发性成分

利用气质联用对沉香燃烟粒相物中的挥发性化合物进行定性及半定量检测,并对萃取溶剂、溶剂用量、振荡时间进行优化。最终选定二氯甲烷为萃取溶剂,溶剂用量为30 m L,振荡时间为30 min;对人工沉香和天然沉香燃烟粒相物谱图进行了分析,共鉴定出123种物质,主要为一些小分子挥发性物质、降解糖、单萜及含甲氧基的化合物,其中有26种物质具有各种香气特征的常用于食品香料的制备,在天然沉香燃烟中,26种具香气的物质所占鉴定物质总量的百分比高于人工沉香。