2015. J. Anim.Sci. 93(8):4070-4078
抗氧化劑對DDGS中油脂和提煉玉米油在高溫高濕環(huán)境下油脂過氧化的影響
A. R. Hanson, P. E. Urriola, L.J. Johnston和G. C. Shurson
本試驗研究了抗氧化劑、DDGS油脂含量、提煉玉米油質(zhì)量、儲存時間對油脂過氧化的影響。試驗共選取4個樣品，一個低油DDGS（LO-DDGS，5.0%粗脂肪），一個高油DDGS（HO-DDGS，13.0%粗脂肪），以及2個提煉玉米油（DCO-1和DCO-2，水分、不溶性雜質(zhì)、非皂化物含量分別為1.20、0.08、0.48%和1.20、0.01、0.1%)。將每個樣品分為18個小樣，每個DDGS小樣約908g，提煉玉米油小樣約2kg。隨機分為3個處理組，對照組（無抗氧化劑添加）、Rendox-CQ（REN組，1000 mg/kg粗脂肪）、Santoquin-Q4T（SAN組，1500mg/kg粗脂肪）。小樣混勻后分為三份，一份立即-20℃冷凍（初始值），另兩份在高溫高濕環(huán)境下（38.6±0.1℃，94.0±0.3%相對濕度）分別保存14和28天。運用SAS的混合模型，以初始值為協(xié)變量，分析原料、抗氧化劑、儲存時間對過氧化的影響及影響因子之間的互作。當儲存時間從14天延長至28天時，提煉玉米油和DDGS的過氧化值（PV）、茴香胺值（AnV）、硫代巴比妥酸反應產(chǎn)物（TBARS）增加了3-4倍（P＜0.05）。儲存28天后，提煉玉米油-1和高油DDGS的過氧化值（分別為12.3±0.3和12.6±0.3mEq O2/kg油）高于提煉玉米油-2和低油DDGS（9.6±0.3和9.3±0.3mEq O2/kg油）。TBARS（對照組為11.0±0.2 mg丙二醛 Eq/kg油）和茴香胺值（AnV，對照組為6.5±0.2）在添加REN和SAN抗氧化劑組中均有降低（P< 0.05）。但是抗氧化劑組之間TBARS和AnV差異并不顯著，REN和SAN組的TBARS分別為6.1±0.2、5.9±0.2mg丙二醛Eq/kg油，AnV分別為1.9±0.2、1.8±0.2。儲存14天和28天后，原料的過氧化值在添加抗氧化劑后有顯著降低（對照組為16.0 mEq O2/kg），并且SAN組過氧化值高于REN組（分別為8.8±0.2、8.0±0.2 mEq O2/kg）。總之，DDGS和提煉玉米油在38.6℃和94.0%相對濕度儲存28天情況下添加抗氧化劑能減少一半過氧化，但是均不能完全消除過氧化。
Impact of synthetic antioxidants on lipid peroxidation of distiller's dried grains with solubles and distiller's corn oil stored under high temperature and humidity conditions
A. R. Hanson, P. E. Urriola, L.J. Johnston and G. C. Shurson
This experiment evaluated the effect of antioxidants, oil content in distiller's dried grains with solubles(DDGS), quality of distiller's corn oil, and storage time on lipid peroxidation. A source of low-oil DDGS (LO-DDGS; 5.0% ether extract [EE],as-fed basis), high-oil DDGS (HO-DDGS; 13.0% EE, as-fed basis), and 2 sources of distiller's corn oil (DCO; 1.20, 0.08, and 0.48% moisture, insoluble impurities, and unsaponifiables [MIU], respectively [DCO-1], and 1.20, 0.01,and 0.10% MIU, respectively [DCO-2]) were obtained. Each of the 4 ingredients was divided into 18 representative subsamples (approximately 908 g for DDGS or 2 kg of DCO). Six subsamples of each ingredient were mixed with either nosupplemental antioxidants (CON), Rendox-CQ (REN; 1,000 mg/kg EE; Kemin,Industries, Des Moines, IA), or Santoquin-Q4T (SAN; 1,500 mg/kg EE; Novus International, St. Louis, MO). Each mixture (n = 72) was split into thirds, and 1 portion was immediately frozen at –20°C (d 0). Two portions were stored underhot (38.6 ± 0.1°C) and humid conditions (94.0 ± 0.3% relative humidity) for 14or 28 d. The MIXED procedure of SAS was used to evaluate the effects of ingredient, antioxidant, storage time, and interactions, with d-0 values used as a covariate. From d 14 to 28, peroxide value (PV), p-anisidine value (AnV), and thiobarbituric acid reactive substances (TBARS) of DCO and DDGS increased by 3-to 4-fold (P < 0.05). Over the entire storage period, PV of DCO-1 and HO-DDGS (12.3 ± 0.3 and 12.6 ± 0.3 mEq O2/kg oil, respectively) exceeded (P< 0.05) that of DCO-2 and LO-DDGS (9.6 ± 0.3 and 9.3 ± 0.3 mEq O2/kg oil,respectively). Adding REN or SAN (P < 0.05) reduced TBARS and AnV relative to CON (TBARS = 11.0 ± 0.2 mg malondialdehyde Eq/kg oil and AnV = 6.5 ± 0.2) over the entire period (mean of d 14 and 28), but TBARS and AnV did not differ(P > 0.05) between antioxidants (TBARS = 6.1 ± 0.2 and 5.9 ± 0.2 mgmalondialdehyde Eq/kg oil, respectively, and AnV = 1.9 ± 0.2 and 1.8 ± 0.2 for REN and SAN, respectively). The PV on d 14 and 28 and overall was less (P <0.05) when either antioxidant was added relative to CON (16.0 mEq O2/kg) and was greater for ingredients treated with SAN (P < 0.05) compared with REN(8.8 ± 0.2 and 8.0 ± 0.2 mEq O2/kg oil for SAN and REN, respectively). In summary, antioxidants reduced peroxidation of DDGS and DCO by approximately 50% during 28 d of storage at 38.6°C and 94.0% relative humidity, but neither antioxidant completely stabilized the ingredients.
