中国农业科学
中國農業科學
중국농업과학
SCIENTIA AGRICULTURA SINICA
2015年
9期
1807-1817
,共11页
王立峰%陈超%杨精华%陈静宜%汪海峰%鞠兴荣
王立峰%陳超%楊精華%陳靜宜%汪海峰%鞠興榮
왕립봉%진초%양정화%진정의%왕해봉%국흥영
大米%脂肪酸%总酸%气相色谱%胚乳细胞
大米%脂肪痠%總痠%氣相色譜%胚乳細胞
대미%지방산%총산%기상색보%배유세포
rice%fatty acids%total acid%gas chromatography%endosperm cell
【目的】由于胚乳失去保护，大米在储藏过程中易发生陈化、霉变等问题，致使其品质劣变甚至丧失食用价值。通过测定储藏过程中大米游离脂肪酸、总酸含量、脂肪酸组成和含量，观察大米横断面胚乳细胞、淀粉颗粒微观结构，探讨大米品质劣变原因，为大米储藏技术提供参考。【方法】以粳稻99号大米为对象，进行人工模拟储藏试验：采用编织袋、自然密闭缺氧、抽真空3种包装方式，置于温度为15、25和30℃（60%湿度）的人工气候箱中储藏180 d，每个月进行一次品质指标测定；测定大米储藏过程中脂肪酸值、总酸值的变化，利用气相色谱分析脂肪酸组成及含量变化，利用扫描电镜观察大米横断面胚乳细胞形态，探索脂类及横断面胚乳结构导致大米品质陈化的机理及品质劣变后淀粉颗粒微观形态的变化规律。【结果】①储藏过程中，编织袋及自然密闭缺氧包装的大米游离脂肪酸及总酸含量皆呈现急剧上升趋势，当品质劣变严重时两者含量反而下降；抽真空包装的大米游离脂肪酸及总酸含量均保持在较稳定的水平，且储藏温度对其含量影响不显著；②脂肪酸组成中含量最多的是亚油酸、油酸和棕榈酸，这3种脂肪酸含量占总脂肪90%以上。包装方式及储藏温度对各脂肪酸组成影响不同。除了花生酸（C20：0）及二十二烯酸（C22：1）外，其余脂肪酸受包装方式影响较大；而储藏温度仅与豆蔻酸（C14：0）和山嵛酸（C22：0）有显著性关系，对其余脂肪酸影响不大。脂肪酸变化规律符合：高不饱和脂肪酸含量随温度升高而降低，多不饱和脂肪酸与饱和脂肪酸及单不饱和脂肪酸间呈现显著负相关，具体表现为硬脂酸（C18：0）与亚油酸（C18：2）、亚麻酸（C18：3）；油酸（C18：1）与亚油酸、亚麻酸皆呈现明显的“此消彼长”现象。③新鲜大米淀粉粒以复粒形式存在，形状较大，表面有较厚的膜，排列整齐有序，两侧以片状的细胞间断面居多，放射状结构清晰可见。陈化加剧的大米胚乳细胞横断面结构松散无序，细胞内断面多于细胞间断面，横断面上可观测到“小孔”及一些分散在淀粉体周围的蛋白体和脂肪滴；细胞壁的完整性受到破坏致使复粒崩解并可见大量单粒细胞，一部分单淀粉粒形状近圆型，棱角较钝；细胞间的棱角模糊，放射状结构变得模糊甚至消失。【结论】编织袋及自然密闭缺氧包装的大米陈化劣变较为严重，储藏过程中其脂肪酸值、总酸值急剧上升后下降，胚乳表面光滑度变差、小孔数量及表面蛋白质膜的翘起变多，辐射状趋势渐渐消失。抽真空包装可以有效延缓大米品质劣变进程。
【目的】由于胚乳失去保護，大米在儲藏過程中易髮生陳化、黴變等問題，緻使其品質劣變甚至喪失食用價值。通過測定儲藏過程中大米遊離脂肪痠、總痠含量、脂肪痠組成和含量，觀察大米橫斷麵胚乳細胞、澱粉顆粒微觀結構，探討大米品質劣變原因，為大米儲藏技術提供參攷。【方法】以粳稻99號大米為對象，進行人工模擬儲藏試驗：採用編織袋、自然密閉缺氧、抽真空3種包裝方式，置于溫度為15、25和30℃（60%濕度）的人工氣候箱中儲藏180 d，每箇月進行一次品質指標測定；測定大米儲藏過程中脂肪痠值、總痠值的變化，利用氣相色譜分析脂肪痠組成及含量變化，利用掃描電鏡觀察大米橫斷麵胚乳細胞形態，探索脂類及橫斷麵胚乳結構導緻大米品質陳化的機理及品質劣變後澱粉顆粒微觀形態的變化規律。【結果】①儲藏過程中，編織袋及自然密閉缺氧包裝的大米遊離脂肪痠及總痠含量皆呈現急劇上升趨勢，噹品質劣變嚴重時兩者含量反而下降；抽真空包裝的大米遊離脂肪痠及總痠含量均保持在較穩定的水平，且儲藏溫度對其含量影響不顯著；②脂肪痠組成中含量最多的是亞油痠、油痠和棕櫚痠，這3種脂肪痠含量佔總脂肪90%以上。包裝方式及儲藏溫度對各脂肪痠組成影響不同。除瞭花生痠（C20：0）及二十二烯痠（C22：1）外，其餘脂肪痠受包裝方式影響較大；而儲藏溫度僅與豆蔻痠（C14：0）和山崳痠（C22：0）有顯著性關繫，對其餘脂肪痠影響不大。脂肪痠變化規律符閤：高不飽和脂肪痠含量隨溫度升高而降低，多不飽和脂肪痠與飽和脂肪痠及單不飽和脂肪痠間呈現顯著負相關，具體錶現為硬脂痠（C18：0）與亞油痠（C18：2）、亞痳痠（C18：3）；油痠（C18：1）與亞油痠、亞痳痠皆呈現明顯的“此消彼長”現象。③新鮮大米澱粉粒以複粒形式存在，形狀較大，錶麵有較厚的膜，排列整齊有序，兩側以片狀的細胞間斷麵居多，放射狀結構清晰可見。陳化加劇的大米胚乳細胞橫斷麵結構鬆散無序，細胞內斷麵多于細胞間斷麵，橫斷麵上可觀測到“小孔”及一些分散在澱粉體週圍的蛋白體和脂肪滴；細胞壁的完整性受到破壞緻使複粒崩解併可見大量單粒細胞，一部分單澱粉粒形狀近圓型，稜角較鈍；細胞間的稜角模糊，放射狀結構變得模糊甚至消失。【結論】編織袋及自然密閉缺氧包裝的大米陳化劣變較為嚴重，儲藏過程中其脂肪痠值、總痠值急劇上升後下降，胚乳錶麵光滑度變差、小孔數量及錶麵蛋白質膜的翹起變多，輻射狀趨勢漸漸消失。抽真空包裝可以有效延緩大米品質劣變進程。
【목적】유우배유실거보호，대미재저장과정중역발생진화、매변등문제，치사기품질렬변심지상실식용개치。통과측정저장과정중대미유리지방산、총산함량、지방산조성화함량，관찰대미횡단면배유세포、정분과립미관결구，탐토대미품질렬변원인，위대미저장기술제공삼고。【방법】이갱도99호대미위대상，진행인공모의저장시험：채용편직대、자연밀폐결양、추진공3충포장방식，치우온도위15、25화30℃（60%습도）적인공기후상중저장180 d，매개월진행일차품질지표측정；측정대미저장과정중지방산치、총산치적변화，이용기상색보분석지방산조성급함량변화，이용소묘전경관찰대미횡단면배유세포형태，탐색지류급횡단면배유결구도치대미품질진화적궤리급품질렬변후정분과립미관형태적변화규률。【결과】①저장과정중，편직대급자연밀폐결양포장적대미유리지방산급총산함량개정현급극상승추세，당품질렬변엄중시량자함량반이하강；추진공포장적대미유리지방산급총산함량균보지재교은정적수평，차저장온도대기함량영향불현저；②지방산조성중함량최다적시아유산、유산화종려산，저3충지방산함량점총지방90%이상。포장방식급저장온도대각지방산조성영향불동。제료화생산（C20：0）급이십이희산（C22：1）외，기여지방산수포장방식영향교대；이저장온도부여두구산（C14：0）화산유산（C22：0）유현저성관계，대기여지방산영향불대。지방산변화규률부합：고불포화지방산함량수온도승고이강저，다불포화지방산여포화지방산급단불포화지방산간정현현저부상관，구체표현위경지산（C18：0）여아유산（C18：2）、아마산（C18：3）；유산（C18：1）여아유산、아마산개정현명현적“차소피장”현상。③신선대미정분립이복립형식존재，형상교대，표면유교후적막，배렬정제유서，량측이편상적세포간단면거다，방사상결구청석가견。진화가극적대미배유세포횡단면결구송산무서，세포내단면다우세포간단면，횡단면상가관측도“소공”급일사분산재정분체주위적단백체화지방적；세포벽적완정성수도파배치사복립붕해병가견대량단립세포，일부분단정분립형상근원형，릉각교둔；세포간적릉각모호，방사상결구변득모호심지소실。【결론】편직대급자연밀폐결양포장적대미진화렬변교위엄중，저장과정중기지방산치、총산치급극상승후하강，배유표면광활도변차、소공수량급표면단백질막적교기변다，복사상추세점점소실。추진공포장가이유효연완대미품질렬변진정。
Objective]Due to the loss of protection of endosperm, rice prones to aging during storage, mildew and other issues, which resulted in edible quality deterioration or even lost edible value. The aim of this study was to explore the reasons for the deterioration of rice quality by measuring the content of total acids and free fatty acids, changes in fatty acid composition and content, microscopic structure of cross-sectional endosperm cells or starch granules of rice, and to provide reference for storage technology of rice.[Method]The No. 99 japonica rice packaged in woven, natural airtight anoxia and vacuum was simulated storaged in artificial climate chamber at a temperature of 15, 25, and 30℃ under 60% RH for 180 d, then the quality indicators and morphology of rice were measured every month. The aging mechanism of rice and variation of starch granules morphology caused by lipids and cross-sectional structure of endosperm after deterioration were explored by determining the variation of fatty acid and total acid value, the changes of fatty acid composition and content were analyzed by gas chromatography, and the cross section of rice endosperm cell morphology was observed by scanning electron microscopy.[Result]It was found from the study that the free fatty acids and total acid contents of rice packaged in woven and natural airtight anoxia increased sharply in initial process while decreased with a serious deterioration of the quality. The free fatty acids and total acid contents of rice packaged in vacuum maintained at a relatively stable level while the storage temperature had no significant effect on its content. The most abundant fatty acids were linoleic acid, oleic acid and palmitic acid,which accounted for more than 90% of total fats. Packaging methods and storage temperature had a great impact on various fatty acids. In addition to arachidonic acid (C20:0) and docosenoic acid (C22:1), the other kinds of fatty acids were greatly influenced by packaging methods. The storage temperature had a significant relationship with myristic acid (C14:0) and behenic acid (C22:0) while had little effect on the rest of the fatty acids. The changes of fatty acids agreed with the results that the amount of highly unsaturated fatty acids decreased with increasing temperature, these data also demonstrated negative correlations between polyunsaturated fatty acids (stearic acid (C18:0) and oleic acid (C18:1)) and saturated or monounsaturated fatty acids (linoleic acid (C18:2) or linolenic acid (C18:3)). The starch grains of fresh rice exist in a compound grain form with a large shape and a thick film on the surface, neat and orderly arranged with clear radial section in both sides of the sheet between the cells. The structure of endosperm cell cross-section became sloppy and disorderly, while the number of intracellular sections were more than that of intercellular sections. In addition, some “small holes” can be observed in sections with some protein and fat droplets scattered in the amyloplast. The compound starch granule broke into a large number of single granulocytes due to the damage of cell wall. Part of the shape of single starch granules became nearly circular with some blunt edges. And the radial structure became blurred or even disappeared when aging seriously.[Conclusion]The value of fatty acids and total acid showed an upward trend first and then a downward trend, the smoothness of endosperm surface deteriorated, and the number of holes and tilt of surface proteins film increased, as well as the radial structure trend disappeared gradually during storage. The rice quality deterioration seriously with woven and natural hypoxic packaging, it could delay the deterioration process of rice quality with vacuum packaging effectively.
