A comparative study of oat (Avena sativa) cultivars as brewing adjuncts

Brewing with high levels of unmalted oats (Avena sativa) has proven to be successful despite their high contents of β-glucan, protein, and fat. However, little is known about the effect of different oat cultivars on the quality and processability of mashes and worts. Therefore, the aim of this study was to compare the mashing performance of eight oat cultivars, selected because of their low contents of β-glucan, protein, fat, and/or high starch content, when substituting 20 or 40 % barley malt. For this purpose, seven husked (A. sativa L. ‘Lutz’, ‘Buggy’, ‘Galaxy’, ‘Scorpion’, ‘Typhon’, ‘Ivory’, ‘Curly’) and one naked oat cultivar (A. sativa var. nuda ‘NORD 07/711’) were fully characterized using standard methods, Lab-on-a-Chip capillary electrophoresis, and scanning electron microscopy. The rheological behavior of mashes containing up to 40 % of each oat cultivar was measured during mashing by applying a Physica MCR rheometer. In addition, the quality of worts obtained from laboratory-scale mashing trials was analyzed particularly with regard to their cytolytic, proteolytic, and amylolytic properties. The substitution of up to 40 % barley malt with husked or naked oats resulted in significantly higher pH values, β-glucan contents, and viscosities as well as significantly lower soluble nitrogen and polyphenol contents, color values, filtration rates, and apparent attenuation limits. Naked oats contained significantly less β-glucan as well as more protein and starch than the seven husked oat cultivars. The replacement of barley malt with naked oats resulted in a constant extract yield, whereas the use of husked oats caused significant extract losses.     

Effect of naked oats in the dairy cow's diet on the oxidative stability of the milk fat

Oxidative stability of milk fats from cows offered naked oats- and barley-based diets were compared in shelf-life tests using the Schaal Oven Test at 63°C, and determination of peroxide and thiobarbituric acid values. Milk fat from cows offered the diet containing naked oats, although containing a higher proportion of monounsaturated fatty acids, had a significantly longer oxidation induction period (13 days) than milk fat from cows offered the control (barley-based) diet (9 days). However, sensory testing of the milk fats indicated that a perceptible odour difference was apparent between stored (63°C) and unstored milk fats after 3 days of storage irrespective of the diet fed. It is possible that the odours perceived may have originated from the cows' diets or from hydrolytic rancidity reactions. The difficulties of relating chemical and sensory testing of the oxidative deterioration of milk fat or butter are underlined. © 1998 SCI.     

全籽粒莜麦微波预熟化工艺优化

以莜麦为原料,用微波技术对莜麦全籽粒进行预熟化处理,利用单因素法和响应面试验优化产品工艺,得到莜麦预熟化的最佳工艺参数为微波时间70 s、微波温度70℃、微波功率800 W,在此条件下,莜麦的糊化度为93.77%。影响莜麦预熟化的因素依次为微波温度>微波时间>微波功率。经预熟化处理后莜麦外观籽粒保持完整,可以达到产品售卖的效果。     

Natural occurrence of Fusarium mycotoxins of the 1990 barley crop in Korea.

During the barley harvest in June 1990, there was a great deal of rainfall and high humidity in the southern part of Korea, and natural occurrence of Fusarium mycotoxins was suspected in barley samples. The samples of undergrade barley were obtained from four provinces and analysed for the presence of deoxynivalenol (DON) and nivalenol (NIV) by gas chromatography and zearalenone (ZEN) by high performance liquid chromatography. Of 37 samples, 33, 37 and 10 were positive for DON, NIV and ZEN, respectively. The husked barley contained 29-677 ng/g for DON, 114-1546 ng/g for NIV and 183-1416 ng/g for ZEN. The naked barley contained 38-645 ng/g for DON, 85-4569 ng/g for NIV and 40-1081 ng/g for ZEN. The average concentration of NIV in naked barley was higher than that in husked barley, but the average concentration of DON in husked barley was higher than that in naked barley. The survey indicates that the 1990 barley crop in Korea was heavily contaminated with Fusarium mycotoxins.     

Color and Oxidative Rancidity of Gamma and Electron Beam-Irradiated Boneless Pork Chops

Color and oxidative rancidity were determined for chilled (3 ± 2°C) and frozen (?17 ± 3°C) boneless pork chops packaged in vacuum or air and irradiated to an absorbed dose of 0, 1.5 or 2.5 kGy (chilled) or 0, 2.5 or 3.85 kGy (frozen) of electron beam or cobalt⁶⁰ irradiation. Irradiation of vacuum-packaged chops produced redder, more stable (color and rancidity) product. More pronounced oxidative rancidity and less stable display color were noted for samples irradiated in aerobic packaging. Irradiation source had varying but limited effects on color and rancidity. Optimum packaging conditions can control color and rancidity changes in boneless chops, thereby enabling irradiation to be a useful intervention technology.     

Milk yield and composition of dairy cows fed concentrate based on naked oats.

A 1.5-yr study was designed to determine the effects of feeding isonitrogenous and isoenergetic concentrates based on naked oats, corn, or a mixture (50: 50 on as-fed basis) of naked oats and corn on milk yield and composition. In vitro dry matter (DM) digestibility and ruminal degradabilities of DM, N, and starch of naked oats were compared with those of covered oats. Twenty-seven multiparous Holstein cows were blocked by similar calving date and assigned to 9 replicates. All cows were fed a mixture of grass silage, protein supplement, concentrate, and a vitamin and mineral mix for ad libitum intake. Treatment diets were fed from 3 to 36 wk of lactation. Milk yield and composition, yield of 4% fat-corrected milk, and yield of protein and fat were similar among treatments. Ruminal effective degradabilities of DM were higher for naked oats than for covered oats, but the ruminal degradabilities of crude protein and starch were similar. The rapidly degradable fractions of DM, crude protein, and starch were greater for naked than covered oats; the potentially degradable fractions were less. In vitro DM digestibility of naked oats was higher than was that of covered oats. Naked oats may be a good alternative to corn for milk yield.     

Comparison of the Sensory Quality and Oxidative Rancidity Status of Frozen-Cooked Mussels (Mytilus edulis L.)

Sensory acceptability and tissue-specific occurrence of oxidative rancidity was investigated among a commercial sample of frozen-cooked mussels and Prince Edward Island (P.E.I.) mussel meats held under a range of frozen storage regimes. P.E.I. mussels stored at - 30°C or - 60°C yielded the most acceptable sensory quality. Sensory and oxidative rancidity status of the commercial product most closely reflected P.E.I. samples held under marginal storage temperatures (- 12°C). Digestive gland tissue demonstrated pronounced morphometric variability and yielded the highest oxidative rancidity values among both commercial and experimental samples. It was concluded that, in addition to marginal storage conditions, tissue-specific morphometric variability, probably resulting from differences in cultivation regions, might influence progression of oxidative rancidity and, hence, sensory quality among frozen-cooked cultivated mussels.     

The apparent ileal digestibility of amino acids and the digestible energy content of naked oats (Avena sativa cv Bandicoot) fed to growing pigs

An experiment was conducted to determine the apparent ileal digestibility of amino acids and the digestible energy (DE) content of two samples of naked oats (Avena sativa cv Bandicoot) and to compare these parameters in wheat (Triticum aestivum cv Machete) and dehulled oats (groats; Avena sativa cv Echidna). Four Large White male pigs were fitted with simple T-piece ileal cannulae and allocated to experimental diets in a 4×4 Latin square design. Amino acid digestibility coefficients were determined after continuous eight hour collections of digesta over two consecutive days using acid-insoluble ash as an indigestible marker. Digestible energy was determined using grab samples of faeces. No significant difference between the four test cereals was found in the digestibility of all amino acids, except for proline and lysine. The apparent ileal digestibility of lysine in wheat (0·87) and two samples of naked oats (0·89 and 0·82, respectively) was lower (P<0·05) than dehulled oats (0·91). The mean DE value of the naked oats samples was 16·96 MJ kg⁻¹ (air-dry basis). The results suggest that Bandicoot naked oats and dehulled oats are superior amino acid and DE sources to wheat and have potential for use in weaner and grower pig diets. © 1998 SCI.     

不同产地裸燕麦代谢产物差异分析

目的：探究不同地区同一品种裸燕麦中的代谢产物及其差异。方法：以代谢组学研究方法为基础,利用甲醇提取极性代谢组分,三氟乙酰胺(BSTFA)进行衍生化处理,并通过GC-MS技术和NIST数据库确定代谢产物。结果：在两个产地同一品种的裸燕麦中共检测出56种代谢产物,HZ的代谢产物占38种,HQ的代谢产物占45种,包括各种碳水化合物和少量次生代谢物。结论：两个地区的燕麦代谢产物及其含量基本一致,均属于常见化合物。但其中亚油酸、反油酸和棕榈酸等常见化合物的浓度不同,D-葡萄糖酸和吡喃半乳糖等代谢产物具有特异性。     

Genotypic variation in oil and protein in barley grain

Oil content and composition, protein content and grain weight have been estimated in 86 barley genotypes from diverse sources grown in a replicated field experiment. Overall range between genotypes in composition was: oil content, 1.9-4.1 %; palmitic, 21.4-28.7%; stearic, 0.6-1.8%; oleic, 10.4-16.9%; linoleic, 52.4-58.3%; linolenic, 4.5-7.3%. Modern European varieties varied from 2.2-2.8% oil, and oil content was higher in two-rowed than six-rowed types and higher in naked than husked types. Protein content was higher in naked than husked types, but there was no significant difference between the protein content of two- and six-rowed types. Mean grain weight was higher in both two-rowed and in husked types. Oil was positively correlated with grain protein and the proportion of oleic acid, and negatively correlated with the proportions of palmitic and stearic acid. The highest oil contents were found in Rise 1508 and Hiproly which are high-lysine genotypes.     

Glandless Cottonseed, Peanut and Soy Protein Ingredients in Ground Beef Patties: Effect on Rancidity and Othei Quality Factors

Defatted flours and protein concentrates and isolates produced from glandless cottonseed, peanut, and soybean were used in rehydrated state (1:2 dry material/water) to replace 10% of the meat in ground beef patties. Fat content of both all-beef and extended patties was adjusted to 20%. Patties were baked on racks to varying final internal temperatures. Extended patties were compared with all-beef patties for rancidity development, cooking properties, and sensory quality. All the oilseed protein ingredients retarded oxidative rancidity development in cooked refrigerated patties, with the highest antioxidant potential shown by the cottonseed protein ingredients. Extended patties had higher cooked yields than all-beef patties, contamed less fat, and were not significantly different from all-beef patties in sensory quality.     

Lipid-protein interactions as agents of quality deterioration in intermediate moisture meats: An appraisal

The literature on lipid-protein interactions which lead to loss of solubility, complex formation, chain scission and loss of specific amino acids in intermediate moisture foods is reviewed. This knowledge is used to explain reported observations on the quality and nutritive value of proteins in intermediate moisture meats as well as the conflicting reports on the significance of oxidative rancidity and non-enzymic browning in intermediate moisture food systems.     

Assessment of Different Packaging Structures in the Stability of Frozen Fresh Brazilian Toscana Sausage

The aim of this work was to evaluate the effect of different package conditions on the characteristics of Toscana fresh sausage stored for 150?days under freezing. The analyses of lipid oxidation, moisture, pH, acidity, water activity, and counting of psychotrophic microorganisms were carried out along with the storage time for each package (low-density polyethylene with and without vacuum and oxygen permeability of 500?cm³ O₂/m² day atm at 23 ??C; nylon polyester with and without vacuum and permeability of 100?cm³ O₂/m² day atm at 23 ??C; and formal copolymer of ethylene and vinyl alcohol with and without vacuum and oxygen permeability of 5?cm³ O₂/m² day atm at 23 ??C). Results showed that from 60?days of storage, the samples stored using polyethylene without vacuum and nylon 100?cm³ O₂/m² day atm, without vacuum, presented a slight rancidity flavor, statistically different (p?<?0.05) from the other tested ones. After 151?days of storage, a relationship between 2-thiobarbituric acid reactive substances analysis and sensory characteristics could be observed. In this case, the packages without application of vacuum presented higher values in the sensory and oxidative rancidity analyses, configuring flavor of slight to moderate rancidity.     

糯性糙米气调储藏脂质变化的研究

实验研究三种储藏温度（15 ℃、25 ℃,35 ℃）和不同气调储藏（CO2、N2、真空）以及常规储藏方式条件下糯性糙米在不同储藏时间脂类物质的变化,发现储藏温度对糯性糙米脂肪酶活性、过氧化氢酶活性、脂肪含量、脂肪酸值、丙二醛和羰基值变化影响显著,同温度下气调组较常规组储藏对糯性糙米的储藏品质有较好的保护作用。研究表明,低温（15 ℃）条件下真空储藏可以减缓糯性糙米品质劣变。     

Dietary fibre fractions in hulled and naked winter oat grain: effects of cultivar and various agronomic factors

The dietary fibre fractions in two winter cultivars each of hulled oats and naked oats grown on three sites under different agronomic conditions in two years were studied. Overall, soluble non‐starch polysaccharides (NSP) represented some 540 g kg⁻¹ of total NSP, and this did not vary greatly among cultivars. There was a significant (P < 0.001) positive relationship between total and soluble NSP. Within cultivars there was much greater variability in the concentrations of β‐glucans than in soluble NSP, and overall there was no relationship between the concentrations of the two related fractions. Oat cultivar and factors such as year and site where grown significantly (P < 0.01) affected soluble NSP contents. There were some indications that environmental factors such as temperature, rainfall and sunshine hours may have been responsible for the apparent effects of site and year. On a dehulled basis, traditional hulled cultivars contained significantly (P < 0.05) more β‐glucans than the naked types, and the results suggest that selection of oats for dietary or plant‐breeding purposes should be based on β‐glucan rather than soluble NSP concentrations. © 2000 Society of Chemical Industry     

莜麦保健面包的研制

介绍了莜麦面包的制法。结果表明:在面包中添加莜麦及汉生胶,增加了面包的体积和持水性,使面包口感柔软,并且有保健功能。     

Effect of dietary variation,with respect to energy and crude protein levels,on the oxidative rancidity exhibited by frozen porcine muscles

The phenomenon of oxidative rancidity exhibited by porcine muscle tissue when held under conditions of frozen storage is influenced by a number of factors. These factors determine the variability exhibited by different muscles with respect to oxidative rancidity. One such factor which is intimately concerned with the above phenomenon is the level of constituent polyunsaturated fatty acids of the intramuscular lipids. In the case of the intramuscular triglyceride fraction, the level of constituent polyunsaturated fatty acids can be modified by dietary means. An experiment is described in which the effect of different diets on the tendency of minced frozen porcine muscle to undergo oxidation was investigated. The particular diets used varied in energy and protein levels and were typical of the kinds of diets used to improve the growth rates and commercial carcase quality of pigs. The results obtained indicated that the particular diets used had little effect on the fatty acid content of the porcine muscle triglycerides and none on that of the phospholipids. It was in the latter fraction that oxidation was mainly exhibited. The major factor influencing the susceptibility of minced frozen porcine muscle to undergo oxidative rancidity, within the dietary limits of the experiment described, was found to be the ultimate (24 h post mortem) pH level of the muscle concerned.     

EFFECT OF MODIFIED ATMOSPHERE STORAGE ON HAZELNUT QUALITY

Hazelnut quality was studied after storage in selected modified atmosphere conditions. Hazelnuts of the Negret cultivar collected in Tarragona, Spain, were used in the experiments. The shelled and unshelled hazelnuts were stored with different oxygen concentrations (1%, 5%, 10% and 20% O₂) at two different temperatures (7C and 25C). The quality of the hazelnuts during storage was monitored by determining the peroxide value, acid value, K₂₃₂ and K₂₇₀ indices, percentage of unsaturated fatty acids and sensory analysis of the hazelnuts. It was observed that after one year storage period, none of the storage modes had given rise to significant rancidity. It was also confirmed that the shell protected the hazelnut from oxidative deterioration. Nevertheless, storage in atmospheres with oxygen levels lower than 10%, autoxidation was significantly reduced and the low temperature delayed lipid rancidity.     

Peanut and Walnut Rancidity: Effects of Oxygen Concentration and Relative Humidity

Accelerated tests for oxidative rancidity of blanched peanuts, blanched dry-roasted peanuts, blanched oil-roasted peanuts and shelled Persian walnuts were performed at high and low oxygen content at controlled intermediate and low relative humidities. The results confirmed and quantified the importance of oxygen content, relative humidity and roasting process in the oxidative rancidity of peanuts and walnuts. There is a potential to extend shelf-life of roasted peanuts and walnuts by edible coatings with low oxygen permeability or nitrogen-flushing with oxygen barrier packaging. Static headspace chromatography was useful to monitor oxidative rancidity in walnuts and roasted peanuts.     

Effect of heat treatment of sorghum grains on storage stability of flour

Sorghum flour is susceptible to rancidity and develops off-flavor within a short duration when stored. Heat treatment on the development of rancidity after long-term storage of flour was studied. Heat treatment varying in severity was applied to the whole grains of different varieties of sorghum viz., CSH-9, CSH-5, M35-1 and a local variety varying in their morphological features. A trend was seen that when the thermal duration was for a shorter time, the shorter was the storage duration in certain varieties. Exposure of grains to moist heat for 15 min retarded hydrolytic rancidity significantly (p < 0.05) in CSH-5 until 6 months of storage and in the remaining varieties until 8 months of storage, Heat application for 15 min retarded the development of rancidity irrespective of the morphological variations and the oil content. Lipase activity varied among the varieties with CSH-5 recording higher activity when compared to the other varieties. No major differences in the physicochemical properties were observed in flours from 15 min heat-processed grains when compared to flours from unprocessed grains.