REVIEW: Regulatory Aspects of Whole Grain and Whole Grain Foods: Definitions and Labeling

Whole grains have many health advantages. Therefore, many companies are adding whole grains to their products and consumers are looking for these foods in their diets. Creating regulations that encourages industry to formulate products with whole grains and accurately convey the amount of whole grain in the product to the consumer creates many challenges. Furthermore, the label should give enough information to enable the buyer to know whether of the product is delivering a dietarily significant amount of whole grain. Labeling regulations create a level playing field so that consumers know what is in the product and all manufacturers have the same opportunity to express the benefits for their products. To establish regulations regarding whole grains, there first needs to be an agreement as to which grains are included and which are not. Next, a common definition for whole grains and whole grain foods is needed. The AACC International definition of whole grains is the basis for many definitions adopted by regulatory bodies and used in industry (AACC International Whole Grain Task Force and Definition; http://www.aaccnet.org/definitions/wholegrain.asp ). However, as grains are processed in various ways, attention needs to be paid to the effects of these various processes on the proportions of the kernel required to meet the AACC International definition of whole grains. Furthermore, there needs to be a vehicle that tells the consumer the amount of whole grain in a product. Label declaration of the amount of whole grain required and the amount in the product can help consumers make better food choices. The FDA‐approved health claim for whole grains is one way to label whole grain products. Because it is based on product weight, not dry weight, it gives lower moisture products an unfair competitive advantage. The FDA‐approved health claim also requires a fiber amount; this gives an advantage to products such as wheat and barley that have whole grains with higher fiber contents. Traditional processing of foods, such as the making of bulgur, the pearling of barley, and the nixtamalization of corn offer special challenges to creating definitions and regulations.     

Regulatory Aspects for Whole Grain and Whole Grain Food: An EU Perspective

Whole grain and whole grain foods enjoy recommendation as part of many national and international dietary guidelines. However, if the food industry makes claims for the health benefits of whole grain foods, then a raft of regulatory requirements must be met in the European Union (EU). Under the relatively recent EU Regulation on nutrition and health claims made on foods, any nutrition claims about the energy, nutrients, fiber, or other beneficial substances the food contains need to comply with the Annex of that Regulation. As far as health claims are concerned, until the Community list of approved so‐called Article 13 claims is published, food businesses may use any health claims that can be validated by scientific evidence, providing that they meet any specific requirements of the Regulation that are applicable prior to that date and providing they are not 1) prohibited claims or 2) claims referring to a reduction in the risk of disease or a disease risk factor or 3) referring to children's development and health or 4) claims that have been rejected by the EU regulatory procedure. Claims under 2) or 3) require submission of a dossier. Once the Community list of health Article 13 claims is published, then only those claims included in the list or those claims approved following submission of a dossier to the European Food Safety Authority may be used. Whole grain foods making nutrition and health claims will also ultimately have to respect the nutrient profiles that will be established under Article 4 of the Regulation. Various definitions of what counts as a whole grain food have been proposed but none has regulatory standing in EU. The conditions of use that will be documented as part of the EU‐approved list of health claims may in essence establish a definition.     

Promoting Cereal Grain and Whole Grain Consumption: An Australian Perspective

Go Grains Health & Nutrition encourages consumption of grain‐based foods in Australia through activities that promote awareness and understanding of the role of grain foods in a healthy diet. Strategies drive the message of the Australian dietary guidelines that a healthy diet should include at least four servings of grain‐based foods every day (1 serving is equal to two slices of bread). The “Go Grains 4+ Serves a Day” program promotes grain‐based foods (refined and whole grain) through the media, website information, resource development, school education, and food industry involvement. Interest in whole grains is growing, reflected in a shift in bread sales over recent years from white to whole grain. Manufacturers are responding with new and reformulated whole grain product launches and an increasing number of products carry packaging statements about whole grain content. Australian food regulations do not permit health claims in packaging or in advertising. In the absence of official guidelines, Go Grains has developed a whole grain daily target intake for use by food manufacturers in packaging. There are limited data publicly available to describe consumption of grain‐based foods in Australia. The findings of a 2009 survey commissioned by Go Grains help provide insight into consumption trends.     

Whole Grain Wheat Flour Production Using an Ultracentrifugal Mill

Interest has been growing in whole grain products. However, information regarding the influence of the ultracentrifugal mill on whole grain flour quality has been limited. An experiment was conducted to produce whole wheat flour with hard red spring (HRS) wheat using an ultracentrifugal mill. This study determined the effect of centrifugal mill parameters as well as grain moisture (10–16%) on producing whole wheat flour and its final products. Mill parameters studied were rotor speed (6,000–15,000 rpm) and feed rate (12.5–44.5 g/min). Results showed that fine particle size (<150 µm) was favored by low seed moisture content (10–12%) and high rotor speed (12,000–15,000 rpm). Flour moisture content was positively related to seed moisture content. Wheat grain with low seed moisture content (10–12%) milled with high rotor speeds (12,000–15,000 rpm) produced desirable whole grain wheat flour quality, with 70–90% of fine particle size portion and low damaged starch (less than 11%). This whole wheat flour produced uniform and machinable dough that had low stickiness and formed bread with high loaf volume.     

Effects of Cultivars,Organic Cropping Management,and Environment on Antioxidants in Whole Grain Rice

Whole grain rice contains functional antioxidants such as phenolics, flavonoids (including proanthocyanidins), vitamin E homologs (tocopherols and tocotrienols), and γ‐oryzanol that have positive effects on human health. These antioxidants are secondary metabolites in plants that can be induced under external stress. The objectives of this study were to quantify the effects of cultivars, crop management method (organic and conventional), and growing environment on the concentrations of these antioxidants in whole grain rice. Cultivars and environment contributed to a higher percentage of variation in the concentrations of these antioxidants than did crop management method. Cultivars accounted for a greater proportion of the variation than environment for all traits except total tocotrienols and γ‐oryzanol. Cultivars that are high in concentrations of these antioxidants were identified, but no one cultivar contained the highest concentration of all antioxidants evaluated. These cultivar differences indicate that improvement for phytochemical and antioxidant traits can be accomplished through traditional breeding. Because of the limited effect of crop management on these antioxidants, choice of cultivar should be the focus for organic production of whole grain rice high in these antioxidants.     

大粒型水稻材料粒型性状的QTL定位

研究大粒型水稻材料对粒型相关基因的挖掘具有重要作用,同时也能为水稻超高产育种提供优质的种质资源。本研究以大粒型水稻材料lg1与9311杂交衍生的F2遗传分离群体为对象,分别采用2014年、2015年的粒型数据和2年的联合粒型数据,对控制其粒长、粒宽及粒厚的QTL进行初步定位。结果表明,3种情况下共定位到22个相关QTL,其中5个粒长QTL、9个粒宽QTL、8个粒厚QTL,分布于第1、第2、第3、第4、第5、第8和第11号染色体上。3种情况下均检测到QTL的有3个,即粒长QTL q GL-2-1、粒宽QTL q GW-5-1和粒厚QTL q GT-5-1,3个QTL增效等位基因均来自于亲本lg1;此外,有7个QTL在2014年、2015年和2年的联合数据定位中均被检测到,12个QTL只在1年或2年的联合数据定位中被检测到。q GL-2-1、q GW-2-3和q GT-2-3处于同一标记区间RM5812~RM13174,推测可能受同一粒型基因控制,是新的粒型QTL位点。主效QTL q GL-1-2和q GW-11-1可能是新的控制粒型QTL位点,其余检测到的QTL所在的大部分标记区间已有粒型QTL被定位或克隆。本研究结果为大粒水稻lg1粒型基因的精细定位及克隆奠定了基础。     

Rice Grain Morphological Characteristics Correlate with Grain Weight and Milling Quality

Using image analysis technology, the morphological measurements of paddy, brown (BR), and milled (MR) grains of 408 rice (Oryza sativa L.) lines representing a wide range of grain morphology were obtained, and the measurements' relationships with grain weight, milling quality, and chalkiness were investigated. The principal component analysis identified two morphological traits with a total variance of 95.7% in MR. Weight of MR was modeled as a function of the principal components using linear regression (R² = 0.95). For milling quality measurements, dominance analyses indicated that single grain weight of the paddy and BR grains were two primary parameters in determination of BR and MR recovery, whereas surface area, perimeter, and diameter were primary parameters that controlled head milled rice (HR) recovery. All measured morphological properties (surface area, perimeter, diameter, length, width, length‐to‐width ratio, roundness, and thickness) and grain weight significantly correlated with percentage of chalky (%C) grain and chalkiness (%C × % area with chalk) for all milled grains. The grain width, roundness, and thickness positively correlated with chalkiness, whereas the length and length‐to‐width ratio negatively correlated with chalkiness. The growing environment significantly affected grain HR recovery, %C grain, and chalkiness but had little effect on grain morphology and weight.     

Effect of Wheat Grain Steaming and Washing on Lipase Activity in Whole Grain Flour

During whole grain flour (WGF) storage, lipase activity causes partial loss of its functionality and the sensory acceptability of products produced from it. The objective of this research was to evaluate the effect of steaming and washing on lipase activity in (fractions of) wheat. Steam treatment conditions were optimized for wheat grains and their bran, shorts, and flour fractions. Lipase activities were determined colorimetrically, as were peroxidase, endoxylanase, and α‐amylase activities. Steaming grains for 180 s effectively inactivated lipase, peroxidase, endoxylanase, and part of the α‐amylase without gelatinizing starch. The work further demonstrated that lipase is mainly, if not only, located in the bran fraction. Separate bran treatment holds promise for obtaining WGF with reduced lipase activity but without altered functional properties. Washing grains did not reduce WGF lipase activity.     

Phosphorus and Mineral Concentrations in Whole Grain and Milled Low Phytic Acid (lpa) 1‐1 Rice

Phytic acid (myo‐inositol‐1,2,3,4,5,6‐hexakisphosphate) is the most abundant form of phosphorus (P) in cereal grains and is important to grain nutritional quality. In mature rice (Oryza sativa L.) grains, the bulk of phytic acid P is found in the germ and aleurone layer, deposited primarily as a mixed K/Mg salt. Phosphorus components and minerals were measured in whole grain produced by either the rice (Oryza sativa L.) cv. Kaybonnet (the nonmutant control) or the low phytic acid 1‐1 (lpa1‐1) mutant, and in these grains when milled to different degrees (10, 12, 17, 20, 22, and 25%, w/w). Phytic acid P is reduced by 42–45% in lpa1‐1 whole grain as compared with Kaybonnet, but these whole grains had similar levels of total P, Ca, Fe, K, Mg, Mn, and Zn. In both genotypes, the concentration of phytic acid P, total P, Ca, Fe, K, Mg, and Mn in the milled products was reduced by 60–90%, as compared with whole grain. However, a trend was observed for higher (25–40%) total P, K, and Mg concentrations in lpa1‐1 milled products as compared with Kaybonnet milled products. The reduction in whole grain phytic acid P in rice lpa1‐1 is accompanied by a 5‐ to 10‐fold increase in grain inorganic P, and this increase was observed in both whole grain and milled products. Phytic acid P was also reduced by 45% in bran obtained from lpa1‐1 grain, and this was accompanied by a 10‐fold increase in inorganic P. Milling had no apparent effect on Zn concentration. Therefore, while the block in the accumulation of phytic acid in lpa1‐1 seed has little effect on whole grain total P and mineral concentration, it greatly alters the chemistry of these seed constituents, and to a lesser but detectable extent, alters their distribution between germ, central endosperm, and aleurone. These studies suggest that development of a low phytate rice might improve the nutritional quality of whole grain, milled rice and the bran produced during milling.     

Flavor Retention and Physical Properties of Rice Cakes Prepared from Coated Rice Grain

Flavored rice cakes are produced commercially by spraying a flavor coating on the cake surface. This study describes a method of making a flavored coating that is applied to individual rice grains before puffing and results in a more uniform flavor distribution. Rice was coated at 5% or 10% levels with coating materials made of jet‐cooked (JC) starch or starch cooked in a water bath (WB), corn starch powder, salt, and a flavor compound. The viscosity of coating materials made with WB starch was twice that of coatings made of JC starch. Rice coated at 10% level had decreased specific density of rice cakes. Rice cakes made from coated grain were similar in appearance to cakes made from uncoated rice but had higher flexural strength. Retention of flavor volatiles after puffing the coated grain was 82.8–56.8% for apple, 72.5–40.3% for anise, and 52.5–24.8% for onion flavor. The flavor volatiles measured in the rice cakes decreased during a three‐month storage period to 49.3% for apple, 25.8% for anise, and 10.1% for onion flavor. Slightly higher retention of flavor volatiles was observed in cakes made with WB starch than in cakes made with JC starch. The difference in retention of flavor volatiles between starch slurry or starch‐oil emulsion treatments was small.     

Polyphenol Oxidase in Wheat Grain: Whole Kernel and Bran Assays for Total and Soluble Activity

Color is a key quality trait of wheat products, and polyphenol oxidase (PPO) is implicated as playing a significant role in darkening and discoloration. In this study, total and soluble PPO activities were characterized in whole kernel assays and bran extracts. In whole kernel assays similar to AACC Approved Method 22–85, four wheat cultivars were ranked the same for both total and soluble (leached) PPO activity with L‐DOPA (diphenol) as the substrate. Total kernel PPO activity was much greater than soluble PPO activity in three hexaploid wheat cultivars, indicating that insoluble PPO was the major contributor to kernel PPO measurements. Tyrosine (monophenol) was an excellent PPO substrate in kernel assays as expected but had no activity as a substrate for soluble PPO. However, soluble PPO activity with tyrosine was activated by the addition of the diphenols chlorogenic acid and caffeic acid. When PPO was assayed in homogenized bran, 89–95% of total PPO activity remained insoluble, associated with the bran particles. The kernel assay detected <2% of PPO measured in an equivalent amount of homogenized bran. However, total PPO activity was 2‐fold higher in Klasic than in ID377s, both when measured in the kernel assay and in homogenized bran, indicating that the kernel assay was an accurate predictor of relative total extracted PPO activity in these two cultivars. Adding detergents (0.1% SDS plus 0.2% NP‐40) to the bran extraction buffer increased both soluble and insoluble PPO activity. Results indicate that relative PPO activities among wheat cultivars are similar in whole kernel and kernel leachate assays, and that the predominant insoluble fraction of PPO, which is relatively uncharacterized, may be largely responsible for wheat product discoloration.     

水稻吸湿过程的内部传质及裂纹机理研究

假定水稻为复合椭球体,在圆柱坐标下,利用有限元法,通过改进的传质模型和粘弹性力学模型,对吸湿环境下水稻颗粒内部水分分布和应力应变分布进行数学模拟。模拟结果表明:水稻吸湿时,表层含水率很快达到平衡水分,中心含水率变化缓慢;水稻颗粒中心所受拉应力最大,表层所受压应力最大,沿颗粒横向从内向外应力由受拉逐渐变为受压;水稻颗粒中心首先形成应力裂纹的可能性最大。利用吸湿实验对模拟结果进行了间接验证。     

Relationship Between Grain,Semolina, and Whole Wheat Flour Properties and the Physical and Cooking Qualities of Whole Wheat Spaghetti

Durum breeding programs need to identify raw material traits capable of predicting whole wheat spaghetti quality. Nineteen durum wheat (Triticum turgidum L. var. durum ) cultivars and 17 breeding lines were collected from 19 different environments in North Dakota and were evaluated for physical and cooking qualities of whole wheat spaghetti. Raw material traits evaluated included grain, semolina, and whole wheat flour characteristics. Similar to traditional spaghetti, grain protein content had a significant positive correlation with cooking quality of whole wheat spaghetti. Stepwise multiple regressions showed grain protein content, mixogram break time, and wet gluten were the predominant characteristics in predicting cooked firmness of whole wheat spaghetti.     

Compression Deformation and Structural Relationships of Medium Grain Cooked Rice

Cooked rice quality is based on a number of factors including texture. Texture and structure of foods are closely related and aspects of the relationship can be explored by correlating compression measurements to structural observations of the compressed material. To obtain compression measurements, single cooked, milled rice grains were compressed in a texture analyzer to a specific percentage (% compression) of the original grain; the uncompressed grain is 0%. The experiment, using single grains in each case, was repeated multiple times. Compression percentages of 20, 30, 40, 50, 60, and 70% were measured against a constant resistance force in the texture analyzer. Structures of cooked rice grains at the various compression levels were compared by brightfield and fluorescence microscopy. The outside of an uncompressed, intact, cooked rice grain is swollen and distorted while the interior has three or more odd‐shaped holes (voids). Each void is largest in the center of the grain and decreases in size toward the peripheral edges becoming fine cracks toward the outermost portion of the void. The voids tended to increase in area up to 40% compression and then decrease in area upon further compression. Percent compression versus resistance force was a curvilinear relationship. With increasing % compression, cell shapes became increasingly more rounded, although there wasn't much effect on the integrity of cell walls with increasing % compression. The degree to which grain structure changed during the various compression tests, combined with the curvilinear behavior of resistance force versus % compression, indicates that the voids and cell walls have an effect on texture.     

Bran Characteristics and Bread‐Baking Quality of Whole Grain Wheat Flour

Variations in physical and compositional bran characteristics among different sources and classes of wheat and their association with bread‐baking quality of whole grain wheat flour (WWF) were investigated with bran obtained from Quadrumat milling of 12 U.S. wheat varieties and Bühler milling of six Korean wheat varieties. Bran was characterized for composition including protein, fat, ash, dietary fiber, phenolics, and phytate. U.S. soft and club wheat brans were lower in insoluble dietary fiber (IDF) and phytate content (40.7–44.7% and 10.3–17.1 mg of phytate/g of bran, respectively) compared with U.S. hard wheat bran (46.0–51.3% and 16.5–22.2 mg of phytate/g of bran, respectively). Bran of various wheat varieties was blended with a hard red spring wheat flour at a ratio of 1:4 to prepare WWFs for determination of dough properties and bread‐baking quality. WWFs with U.S. hard wheat bran generally exhibited higher dough water absorption and longer dough mixing time, and they produced smaller loaf volume of bread than WWFs of U.S. soft and club wheat bran. WWFs of two U.S. hard wheat varieties (ID3735 and Scarlet) produced much smaller loaves of bread (<573 mL) than those of other U.S. hard wheat varieties (>625 mL). IDF content, phytate content, and water retention capacity of bran exhibited significant relationships with loaf volume of WWF bread, whereas no relationship was observed between protein content of bran and loaf volume of bread. It appears that U.S. soft and club wheat bran, probably owing to relatively low IDF and phytate contents, has smaller negative effects on mixing properties of WWF dough and loaf volume of bread than U.S. hard wheat bran.     

Effect of High Night Temperature During Grain Filling on Amyloplast Development and Grain Quality in Japonica Rice

High‐quality japonica rices Yujing 6 and Fangxin 4 were cultured under ambient night temperature (ANT, 19.7°C) and high night temperature (HNT, 26.7°C) in a greenhouse for the analysis of amyloplast development and grain quality during the grain‐filling stage. Results indicated that the HNT treatment had distinct effects on the grain‐filling rate of Yujing 6 and Fangxin 4 1–10 days after anthesis. HNT increased the rate of grain filling by 9.89–40.45% and decreased the accumulation of grain‐filling matter, resulting in inferior appearance and poor milling qualities (e.g., brown rice rate, milled rice rate, head rice rate, imperfect rice rate, chalky rice rate, and chalkiness degree). Results from a rapid viscosity analyzer showed that the HNT treatment decreased the paste viscosity, depending on the rice cultivar. Differential scanning calorimetry results indicated that the gelatinization temperatures of HNT such as onset temperature, peak temperature, and final temperature were all significantly higher than those of ANT. However, HNT had no distinct effects on the X‐ray diffraction pattern of rice starch.     

利用ISSR分子标记研究栽培稻和野生稻亲缘关系

本研究利用ISSR分子标记研究了37份栽培稻和野生稻的亲缘关系。结果表明，18个ISSR引物共扩增133个多态性条带，每个引物平均扩增多态性条带7.4个，扩增产物片段大小在0.1-3.0kb之间。而AA荆垢普通野生稻和栽培稻遗传关系密切，而与非AA型野生稻有一定亲缘关系。聚类分析将37份栽培稻和野生稻明显分为5组，第1组为AA类型的普通野生稻和栽培稻，第2组为疣粒野生稻，第3、4组分别为CC，CCDD染色体组野生稻，第5组为O.Rhychoryza。栽培稻与野生稻的亲缘关系体现了地妥由普通野生稻分化而来，而普通野生稻是从南向北逐渐分化的。本研究还讨论了栽培稻与普通野生稻的进货关系。