本文選題：采后開(kāi)心果 + 射頻　； 參考：《西北農(nóng)林科技大學(xué)》2016年博士論文

【摘要】：開(kāi)心果(Pistacia vera L.)與核桃、巴旦杏和榛子并稱(chēng)世界四大樹(shù)堅(jiān)果(tree nut)。其果仁富含油脂、蛋白質(zhì)、礦物質(zhì)、維生素與植物化學(xué)成分,具有很好的保健功效與藥理作用。近年來(lái),我國(guó)開(kāi)心果消費(fèi)量逐年增加,市場(chǎng)價(jià)格居高不下,屬特種珍貴堅(jiān)果。然而,采后蟲(chóng)害侵染造成的儲(chǔ)藏品質(zhì)損失與精深加工不足形成的產(chǎn)品低端單一問(wèn)題,已嚴(yán)重阻礙我國(guó)堅(jiān)果產(chǎn)業(yè)的發(fā)展。如何控制采后開(kāi)心果蟲(chóng)害,保證儲(chǔ)藏品質(zhì),提高精深加工水平,豐富產(chǎn)品種類(lèi),是我國(guó)堅(jiān)果加工業(yè)發(fā)展中亟待研究與解決的問(wèn)題。本課題以國(guó)內(nèi)外開(kāi)心果主要消費(fèi)品種科曼為研究對(duì)象,利用射頻加熱技術(shù)進(jìn)行采后開(kāi)心果倉(cāng)儲(chǔ)害蟲(chóng)的殺滅研究,并在此基礎(chǔ)上對(duì)射頻殺蟲(chóng)處理后的開(kāi)心果樣品進(jìn)行綜合加工利用研究。具體研究?jī)?nèi)容為:(1)利用終端開(kāi)路同軸探頭技術(shù),測(cè)量了不同含水量與含鹽量開(kāi)心果仁的介電特性,計(jì)算特定頻率下電磁波的穿透深度。(2)研究了開(kāi)心果的射頻殺蟲(chóng)單批次處理工藝,優(yōu)化了射頻加熱的最佳極板間距、冷卻方法與加熱均勻性,明確了射頻殺蟲(chóng)對(duì)開(kāi)心果儲(chǔ)藏穩(wěn)定性的影響。(3)采用射頻殺蟲(chóng)連續(xù)化處理方式,開(kāi)展了射頻加熱均勻性、害蟲(chóng)死亡率、加熱效率、處理量等工業(yè)放大研究。(4)用液壓冷榨法獲得未烘焙、傳統(tǒng)烘焙、微波烘焙三種開(kāi)心果油,針對(duì)上述開(kāi)心果油進(jìn)行了理化特性、香氣成分與氧化穩(wěn)定性研究。(5)以未烘焙與烘焙開(kāi)心果仁經(jīng)冷榨出油后的半脫脂粉為原料,用石油醚浸提獲得全脫脂樣品。測(cè)定并分析了半脫脂與全脫脂兩種開(kāi)心果粉的營(yíng)養(yǎng)成分、功能特性、生物活性及微觀結(jié)構(gòu)。(6)用靜態(tài)稱(chēng)重法測(cè)定了全脂、半脫脂、全脫脂三種開(kāi)心果粉的解吸吸附平衡含水量,確定了最佳等溫線模型,計(jì)算了樣品的單層水含量與等量吸著熱。主要結(jié)論如下:(1)開(kāi)心果仁的介電特性隨頻率升高而減小,其中高含水量樣品(15%)在低頻(100 MHz)范圍內(nèi),介電損耗的減小幅度更為顯著。果仁損耗因子隨含鹽量增加而顯著增大,但介電常數(shù)無(wú)顯著改變。射頻波段果仁損耗因子顯著小于害蟲(chóng),電磁波對(duì)開(kāi)心果與害蟲(chóng)具有潛在的選擇性加熱效應(yīng)。27 MHz射頻殺蟲(chóng)時(shí),開(kāi)心果最大堆疊厚度可達(dá)24 cm,915 MHz微波殺蟲(chóng)時(shí)僅為4-6 cm,射頻加熱更適于進(jìn)行大規(guī)模工業(yè)化殺蟲(chóng)處理。(2)利用27.12 MHz 6 kW中試規(guī)模射頻加熱系統(tǒng)對(duì)1.8 kg帶殼與2.0 kg脫殼開(kāi)心果進(jìn)行殺蟲(chóng)單批次處理,分別僅需5.5和5.6 min即可使中心溫度達(dá)到55°C。射頻殺蟲(chóng)時(shí),兩種開(kāi)心果輔以熱風(fēng)表面加熱、往復(fù)運(yùn)動(dòng)、混合攪拌等措施可以改善加熱均勻性。射頻殺蟲(chóng)處理對(duì)開(kāi)心果品質(zhì)與儲(chǔ)藏穩(wěn)定性無(wú)顯著影響。射頻殺蟲(chóng)連續(xù)化處理中,射頻加熱的均勻性優(yōu)于單批次殺蟲(chóng)處理的加熱均勻性,可快速有效殺滅常見(jiàn)倉(cāng)儲(chǔ)害蟲(chóng)印度谷螟。當(dāng)殺蟲(chóng)處理量為264.3 kg/h時(shí),系統(tǒng)的平均加熱效率為70%。(3)與未烘焙開(kāi)心果仁冷榨油相比,適度烘焙處理,開(kāi)心果油的過(guò)氧化值略有增加,葉綠素含量小幅降低,色澤相對(duì)變暗,總酚含量與抗氧化能力顯著增強(qiáng)。未烘焙開(kāi)心果冷榨油在結(jié)晶過(guò)程中的熱相變峰值溫度分別為-47.15和-19.85°C,融化過(guò)程中分別為-13.11和3.11°C,烘焙處理后油脂的熱相變溫度、融化和結(jié)晶曲線未發(fā)生明顯變化。烘焙能促使開(kāi)心果冷榨油中吡嗪類(lèi)物質(zhì)的形成,其中2-乙基-5-甲基吡嗪,3-乙基-2,5-二甲基吡嗪和3,5-二乙基-2-甲基吡嗪等化合物相對(duì)含量較高,對(duì)烘焙油樣風(fēng)味特征的形成發(fā)揮重要作用。開(kāi)心果冷榨油對(duì)光氧化與自動(dòng)氧化均有較強(qiáng)敏感性,采用不透光容器包裝并添加0.01%(w/w)的特丁基對(duì)苯二酚(TBHQ)或0.02%的抗壞血酸棕櫚酸酯(AP)或0.07%的迷迭香提取物(RME),在室溫條件下儲(chǔ)藏其良好品質(zhì)可至少保持4個(gè)月。(4)全脫脂處理后,開(kāi)心果粉的黃色與綠色值較全脂和半脫脂粉顯著減小。烘焙與未烘焙開(kāi)心果脫脂粉的宏量營(yíng)養(yǎng)素含量無(wú)顯著差異,但烘焙開(kāi)心果脫脂粉的色澤整體偏暗、氨基酸含量有所降低。烘焙處理對(duì)開(kāi)心果粉的功能特性無(wú)顯著影響,但脫脂處理后其吸水/油力、乳化能力、乳化穩(wěn)定性、起泡能力均顯著高于全脂粉,其中全脫脂粉性能最高。烘焙開(kāi)心果半脫脂粉的多酚和黃酮類(lèi)含量最高,分別為792 mg GAE/100 g粉(d.b.)和280.30 mg RE/100 g粉(d.b.)。同時(shí)具有最強(qiáng)的抗氧化能力,DPPH·清除力和鐵氰化鉀還原力分別為78.12和130.51μmol Trolox/g粉(d.b.)。開(kāi)心果脫脂粉中淀粉顆粒為表面光滑的橢圓球狀,直徑介于5-15μm。開(kāi)心果半脫脂粉的蛋白質(zhì)與淀粉顆粒集中分布于表面光滑的連續(xù)結(jié)構(gòu)中,而在全脫脂粉中蛋白質(zhì)與淀粉顆粒分散且表面呈多孔狀。(5)按BET分類(lèi)法,開(kāi)心果全脂粉、半脫脂粉、全脫脂粉的解吸吸附等溫線屬第二類(lèi),曲線呈S形。根據(jù)IUPAC分類(lèi),三種開(kāi)心果粉的解吸吸附滯后現(xiàn)象為H3型。相同溫度與水活度下,全脫脂粉的解吸吸附平衡含水量最高、半脫脂粉次之、全脂粉最低。統(tǒng)計(jì)分析表明:Smith模型為全脂粉等溫線數(shù)據(jù)的最佳模型,Halsey模型為半脫脂粉和全脫脂粉的最佳模型。15-35°C時(shí)開(kāi)心果全脂、半脫脂、全脫脂粉的單分子層水含量分別為2.433-3.404,3.784-4.823和4.987-6.687 g/100 g(d.b.)。25°C平衡含水量2-40%(d.b.)范圍內(nèi),開(kāi)心果全脂、半脫脂、全脫脂粉的等量吸著熱分別為74.67-44.76,99.44-44.75和133.28-44.80 kJ/mol。其中,在低含水量范圍內(nèi),均表現(xiàn)為等量解吸熱大于吸附熱。
[Abstract]:Pistacia Vera L. and walnut, apricot and hazelnut and the world's four big tree nuts (tree nut). Their nuts are rich in oil, protein, minerals, vitamins and phytochemicals, and have good health and pharmacological effects. In recent years, the consumption of pistachios in China has increased year by year, and the market price is high, which is a special and precious firm. However, it has seriously hindered the development of the nut industry in China. How to control the Postharvest pistachio, guarantee the quality of the storage, improve the quality of the intensive processing, and enrich the product types, is an urgent problem in the development of the nut processing industry in China. In order to solve the problem, the subject takes kcoman, the main product of domestic and foreign pistachios, as the research object, and uses the radio frequency heating technology to study the killing of the storage pests in the Postharvest pistachios. On this basis, the synthetic processing and utilization of the pistachio samples after the radiofrequency insecticidal treatment are studied. The specific contents are as follows: (1) using the terminal opening coaxial The probe technique was used to measure the dielectric properties of different water content and salt content, and to calculate the penetration depth of the electromagnetic wave at a specific frequency. (2) a single batch process of radio frequency killing of pistachios was studied. The optimum spacing of the plate, the cooling method and the heating uniformity were optimized, and the storage stability of the radiofrequency insecticide to the pistachios was clear. (3) using radio frequency insecticidal continuous treatment, radio frequency heating uniformity, pest mortality, heating efficiency, processing quantity and other industrial enlargement studies. (4) three kinds of pistachio oil were obtained by hydraulic cold pressing, three kinds of pistachios oil were baked, traditional baking and microwave roasting, and the physicochemical properties, aroma components and oxidation of the above pistachio oil were carried out. The study of stability. (5) the total degreasing samples were obtained from the semi skimmed powder of the baked and baked happy nuts after the cold extraction of oil, and the total degreasing samples were extracted with petroleum ether. The nutritional components, functional properties, biological activity and microscopic structure of two kinds of happy fruit powder, semi degreased and full degreased, were measured and analyzed. (6) the total fat, semi degreasing and whole fat were measured by static weighing method. The best isotherm model was determined by desorption and adsorption of the three kinds of skim fruit powder. The main conclusions were as follows: (1) the dielectric properties of the kernel were decreased with the increase of frequency, of which the high moisture content (15%) decreased in the range of low frequency (100 MHz), and the decrease of dielectric loss was more than that of the high water content. The loss factor of kernel loss significantly increased with the increase of salt content, but there was no significant change in dielectric constant. The kernel loss factor of the radio frequency band was significantly smaller than that of the pest. The electromagnetic wave has a potential selective heating effect on the pistachios and pests.27 MHz radiofrequency, the maximum stack thickness of the pistachios can reach 24 cm, and the 915 MHz microwave killing is only 4. -6 cm, RF heating is more suitable for large-scale industrial insecticidal treatment. (2) using a pilot scale radio frequency heating system of 27.12 MHz 6 kW, the 1.8 kg belt shell and 2 kg shell pistachios are treated with single batch. Only 5.5 and 5.6 min can make the center temperature reach 55 degree C., and two kinds of pistachios are heated on the hot air surface. The reciprocating movement, mixed mixing and other measures can improve the heating uniformity. Radio frequency insecticidal treatment has no significant effect on the quality of pistachios and storage stability. In the radiofrequency continuous treatment, the uniformity of the radiofrequency heating is better than the uniformity of the single batch of insecticidal treatment. It can quickly and effectively kill the India Valley borer, a common storage pest. The average heating efficiency of the system was 264.3 kg/h, and the average heating efficiency of the system was 70%. (3) compared with the cold pressed oil from the non baked happy nuts. The peroxide value of the pistachio oil increased slightly, the content of chlorophyll decreased slightly, the color and lustre darkened, the total phenol content and the antioxidant capacity increased significantly. The peak temperature of the thermal phase transition is -47.15 and -19.85 C respectively. The melting process is -13.11 and 3.11 degree C respectively. The thermal phase transition temperature of the oil after baking is not changed obviously. The baking can promote the formation of pyrazine in the cold squeezing oil of the pistachio, including 2- ethyl -5- methylpyrazine, 3- ethyl -2,5- two methylpyrazine and 3,5-. Two ethyl -2- methyl pyrazine and other compounds have a relatively high relative content and play an important role in the formation of the flavor characteristics of the baked oil. The cold pressed pistachio oil has a strong sensitivity to photooxidation and automatic oxidation. A 0.01% (w/w) of terbutylhydroquinone (TBHQ) or 0.02% ascorbate palmitate (AP) or 0.07 is added to the cold pressed container of the pistachio. The good quality of rosemary extract (RME) could be kept for at least 4 months at room temperature. (4) after full degreasing, the yellow and green value of happy fruit powder decreased significantly than that of full fat and semi degreased powder. There was no significant difference in the macro nutrient content of the baked and roasted pistachio powder, but the color and lustre of the baked pistachio skimmed powder was full. The bakery treatment had no significant effect on the functional properties of the happy fruit powder, but the water absorption / oil capacity, emulsifying ability, emulsifying stability, and foaming ability were significantly higher than that of the whole fat powder after the degreasing treatment, and the full dehydration powder was the highest. The content of polyphenols and flavonoids in the baked pistachio semi degreased powder was 7, respectively. 92 mg GAE/100 g powder (D.B.) and 280.30 mg RE/100 g powder (D.B.). At the same time it has the strongest antioxidant capacity. The DPPH clear force and potassium ferricyanide reduction force are 78.12 and 130.51 micron mol Trolox/g powder (D.B.). The starch granules in the pistachio skimmed powder are smooth and ellipsoidal, and the diameter of the protein with the diameter of 5-15 micron pistachio semi skimmed powder is in diameter. The starch granules were concentrated in the smooth surface of the continuous structure, while the protein and starch granules were dispersed in the full skimmed powder and the surface was porous. (5) according to the BET classification, the desorption isotherm of the pistachio full fat powder, the semi degreased powder and the total degreased powder was of the second class, the curve showed S shape. According to IUPAC classification, the desorption and adsorption hysteresis of three kinds of happy fruit powder After the same temperature and water activity, under the same temperature and water activity, the desorption adsorption equilibrium moisture content of the total degreasing powder is the highest, the half degreasing powder is the second and the whole fat powder is the lowest. The statistical analysis shows that the Smith model is the best model of the whole fat powder isotherm data, and the Halsey model is the best model of the semi degreased powder and the full degreasing powder for.15-35 [C], and the Halsey is semi degreased. The water content of the single molecular layer of full degreasing powder is 2.433-3.404,3.784-4.823 and 4.987-6.687 g/100 g (D.B.).25 / C equilibrium water content 2-40% (D.B.). The whole fat of pistachio, semi degreasing, and the equal amount of absorption heat of the total degrease powder are 74.67-44.76,99.44-44.75 and 133.28-44.80 kJ/mol., respectively. In the range of low water content, the same quantity is equal. The solution heat absorption is greater than the adsorption heat.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：S436.64
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本文編號(hào)：1975226