Migration of mycotoxins into rice starchy endosperm during the parboiling process

Considering the occurrence of rice contamination by mycotoxins and the increase in rice consumption, the present work had the objective of assessing the migration of mycotoxins into the starchy endosperm during the parboiling process, as to propose conditions that provide lower contamination levels. The newly harvested rice grain sample was examined for the natural occurrence of mycotoxins (aflatoxin B₁, aflatoxin B₂, deoxynivalenol, ochratoxin A, and zearalenone); only the presence of aflatoxin B₁ was found (17 ng/g). The samples were then artificially contaminated with deoxynivalenol and zearalenone, and the parboiling process was conducted according to a 2³ factorial planning with central point, having as variables the contamination level deoxynivalenol 720, 1440, and 2160 ng/g, and zearalenone 476, 952, and 1428 ng/g the soaking time (4, 5, and 6 h) and autoclave time (15, 22.5, and 30 min). Mycotoxins aflatoxin B₁ (AFA B₁), deoxynivalenol (DON), and zearalenone (ZEA) were confirmed and determined through gas chromatography. Findings showed a lower migration trend for AFA B₁ under 6 h of soaking and 30 min of autoclaving, for DON under 6 h of soaking regardless of the autoclaving time, and for ZEA under 4 h of soaking and 15 min of autoclaving. This information can contribute to the choice of process parameters that limit the migration of these mycotoxins if they happen in the raw material.     

The bioavailability of iron fortified in whole grain parboiled rice

The present study was to evaluate the bioavailability of iron (Fe) fortified in parboiled rice grain, expressed as Fe uptake by Caco-2 cells after in vitro digestion. The bioavailability of Fe-fortified in the rice grain was closely and positively correlated with increasing concentrations of Fe in the grains of the three cultivars (r = 0.96∗∗). The uptakes of the Fe-fortified in parboiled rice milled for 120 s (34.2, 47.7 and 107 ng ferritin mg protein⁻¹ in three cultivars, respectively) were well above those of the unfortified raw (6.1, 4.9 and 5.7 ng ferritin mg protein⁻¹) or parboiled rice (4.7, 3.6 and 4.4 ng ferritin mg protein⁻¹), the high Fe rice line IR68144-2B-3-2-2 (4.0 ng ferritin mg protein⁻¹) and popular Jasmine rice cultivar KDML 105 (3.9 ng ferritin mg protein⁻¹). Increasing milling time and rinsing the Fe-fortified parboiled rice decreased Fe bioavailability, due to their negative effects on total Fe concentrations in the parboiled rice grains, but uptakes were still well above that of their unfortified raw or parboiled rice grains. Rinsing or washing the Fe-fortified and milled rice grains decreased the bioavailability to 85 ng ferritin mg protein⁻¹ in the YRF cultivar, compared to about 100 ng ferritin mg protein⁻¹ in its non-rinsed grains. Dilute acid-extractable (DAE) Fe was linearly, positively correlated with the uptake of Fe assessed by the in vitro digestion/Caco-2 cell technique (r = 0.90∗∗), which can be used as a rapid method for optimizing levels of bioavailable Fe to be fortified in the parboiled rice by parboiled-rice mills if this Fe-fortification technique should be adopted in south and southeast Asia.     

Folic acid fortification of parboiled rice: Multifactorial analysis and kinetic investigation

Folic acid fortification of parboiled rice has been systematically studied to obtain quantitative insights into the role of key process variables. Parboiling was conducted with brown rice soaked at 70 °C for 1, 2 and 3 h with four different fortificant concentrations added and dried parboiled rice was milled for three durations (i.e. 0, 60 and 120 s). Both residual folate concentration in treated parboiled rice and pH of the soaking water after soaking stages were measured. Multifactorial model was developed to describe the residual folate retention behaviour and suggested that both soaking and milling were significant factors in folic acid fortification. The optimum soaking time was deduced to be 1.97 h. Folate retention rate followed a 1st order kinetics while the rates of natural rice hydrolysis and folate uptake were both time-dependent.     

Addition of grape pomace in the hydration step of parboiling increases the antioxidant properties of rice

The conventional parboiling process decreases the total phenolic compounds (TPC) and the antioxidant activity (AA) of rice. In order to change this nutritional disadvantage, in this research we have proposed an unusual solution. Here, we added grape pomace (agro-industrial waste) in the process during the parboiling as a source of bioactive compounds (BC). An increase in the concentrations of TPC, flavonoids anthocyanins and antioxidant activity was found. Moreover, there was slightly change in the final colour of the rice (which tended towards red) in addition to added proline (NMR spectra), which is an amino acid that is characteristic of grapes. Therefore, we concluded that it is possible to improve the functionality of parboiled rice with the addition of grape pomace, besides promoting the valorisation and use of an agro-industrial waste rich in secondary metabolites.     

Iron fortification and parboiled rice quality: appearance,cooking quality and sensory attributes

BACKGROUND: Iron (Fe) fortification of parboiled rice increases both Fe concentration and bioavailability in milled grains (i.e. white rice). The aim of the present study was to evaluate parboiled rice fortified with 250 and 450 mg Fe kg^?1 paddy rice for its pre‐cooking appearance, cooking quality, basic sensory attributes and overall acceptance in comparison with unfortified parboiled rice in Thailand and local parboiled rice in Bangladesh. RESULTS: Fe fortification at 250 mg Fe kg^?1 paddy rice significantly elevated Fe concentration in white rice to as high as 19.1 mg Fe kg^?1 white rice, compared with 6.2 mg Fe kg^?1 white rice for unfortified parboiled rice, without any adverse impact on consumer acceptance based on the current preliminary assessment. The added Fe was well retained in the cooked rice, with significant residual value for human intake. Panellists in Thailand and Bangladesh did not detect significant differences in the acceptability of parboiled rice fortified at 250 mg Fe kg^?1 paddy rice compared with unfortified and local parboiled rice respectively. However, Fe fortification of parboiled rice at the higher level of 450 mg Fe kg^?1 paddy rice significantly intensified the yellow colour of the grain and changed the off‐flavour, chewiness and flakiness of the cooked Fe‐fortified parboiled rice. This resulted in a low acceptability ranking of parboiled rice fortified at 450 mg Fe kg^?1 paddy rice by panellists in both Thailand and Bangladesh. CONCLUSION: Fe fortification of parboiled rice at an appropriate level (e.g. 250 mg Fe kg^?1 paddy rice) is dosage‐effective and acceptable to rice consumers. Consumer acceptability of Fe‐fortified parboiled rice is closely related to pre‐cooking appearance, cooking quality and sensory attributes. Copyright © 2009 Society of Chemical Industry     

国内外铁强化管理比较研究

铁缺乏是全球最为常见的营养缺乏病之一,也是各国的重要公共卫生问题。针对铁缺乏现状,各国制定了一系列铁强化的政策和法规,以改善缺铁性贫血以及铁缺乏相关疾病。本文就目前国内和部分国家食品铁强化法律法规体系、铁强化剂、铁强化食物载体等方面进行论述,为今后我国铁强化政策的修订提供参考。     

利用乳酸锌强化食品的试验

锌是人体内最重要的微量元素之一。我国的膳食构成中易引起锌缺乏症。本试验利用乳酸锌作为锌强化剂对豆米粉,Vc固体饮料,豆奶进行了强化试验,试验结果表明:强化锌工艺简单,产品质地、风味不受显著影响,在食品中用乳酸锌强化锌是可行的     

Key factors affecting Fe density in Fe-fortified-parboiled rice: Parboiling conditions,storage duration,external Fe-loading rate and genotypic differences

The present study evaluated the key factors affecting the efficiency of iron (Fe) penetration into the endosperm in parboiled rice of different varieties. It also investigated effects of storage time on Fe bio-accessibility, rice colour and Fe retention after rinsing. Rice grains of three varieties were fortified with an increasing range of Fe-fortification rates during the parboiling process, under two typical parboiling conditions, which are ambient soaking temperature for 24 h and 60 °C soaking temperature for 6 h at neutral (6.0–6.5) and acidic pH (3.0–3.5). Soaking of paddy rice, at 60 °C in acidic water for 6 h before steaming, was found to be better for maximising the Fe concentration in white-parboiled rice than the former ambient soaking. Under this parboiling condition, adding 250 mg Fe kg⁻¹ of paddy rice, at soaking, produced the most desirable Fe concentration in white rice, ranging from 17.5 to 25.4 mg kg⁻¹ among the rice varieties tested. The concentrations of Fe in parboiled white rice exhibited an exponential increase with increasing concentrations of Fe in the soaking water in all varieties, which were linearly related to Fe concentration of brown rice (r = 0.96∗∗, p < 0.01). The colour of the parboiled rice fortified with Fe was initially light yellow, with variation among rice varieties, but it did become slightly darker after 16 weeks of storage, probably because of Fe oxidisation. This may be related to decreasing bio-accessibility after 20 weeks of storage. Storage, however, did not affect the total Fe retention after rinsing, though the retention rate was variety-dependent. Information about parboiling will provide the basis for formulating an optimal industry protocol for producing Fe-fortified-parboiled rice, which can be further refined in pilot studies on the industrial scale.     

Food fortification strategy--preventing iron deficiency anemia: a review

Iron deficiency anemia (IDA) is a significant challenge in developing countries. It increases the risk of premature delivery and low birth weight. In children, IDA retards growth, impairs cognitive performance, and reduces physical activity. It also accelerates the mortality and morbidity rate in women. The key factors responsible include dietary elevated iron demand, socioeconomic, and disease status. To overcome IDA, disease control measures, dietary diversification, supplementation and iron fortification in food have been adopted. Iron fortification in food is considered a long term and sustainable strategy in the present scenario. For an efficient fortification program, the combination of iron fortificants and food vehicle must be safe, acceptable, and consumed by the target population. Moreover, it should not adversely affect acceptability and stability of the end product.     

国家营养改善项目--铁强化酱油

全球约有1／5人患缺铁性贫血,我国儿童贫血率在25％左右,妇女贫血率在20％左右,孕妇贫血率高达35％,成年男子贫血率则在10％左右。铁缺乏及贫血严重影响儿童的体格、智力发育及其成年后从事体力和脑力劳动的能力,对育龄妇女则不仅危害其自身健康,更可能波及下一代健康。中国疾病预防控制中心营养与食品安全所研制出的乙二胺四乙酸铁钠(NaFeEDTA)强化酱油具有吸收率高,不改变酱油自身的食用方法和口感,改善贫血效果显著以及经济安全等特点。随着人们对铁缺乏的重视以及各方的鼎立支持,铁强化酱油将得到全力推广,使百姓真正受益于铁强化酱油。     

Micronutrient fortification of wheat flour: Recent development and strategies

Deficiencies of iron, zinc and vitamin A have been a focus of the governments and world organizations for decades and extensive efforts are being made to address this malnutrition. Being a popular and most common dietary staple of the population living in sub-continent and developing countries, wheat flour (WF) has gained a significant attention as a suitable vehicle for micronutrient fortification. Fortification of wheat flour has been established as an appropriate strategy to curtail micronutrient deficiencies especially in the developing economies. Extent of the prevalence of micronutrient deficiencies, their consequences, selection of a suitable vehicle, choice of fortificants and their levels and storage stability, acceptability and bioavailability of iron and zinc fortified WF are the key points of discussion in the current review. This review further highlights multifaceted issues pertaining to the appropriateness and suitability of fortification over other intervention strategies, ecological needs and fortification success stories and advantages of simply adding fortificants to flour to meet nutritional requirements of vulnerable groups. The authors have attempted to encompass the subject matter based on their research endeavors made in this direction.     

Quality changes in HTST processing of rice parboiling

Paddy soaked to saturation level, when treated at a high temperature for a short time in a mechanical sand roaster is parboiled and dried in a single pass of 47 s duration. The extent of drying depends on the sand temperature. The sand temperature is critical as it decides the associated quality changes in the milled rice. Even at a sand temperature of 125°C, paddy could fully be parboiled but with mild effect. The parboiling became severe at high temperatures. Roasting the soaked paddy at 250°C, reduced the cooking time of the resultant milled rice. A sand temperature of 125–150°C was considered suitable for producing normal parboiled rice by this technique.     

Effect of pre-steaming on production of partially-parboiled rice using hot-air fluidization technique

Fluidization technique was widely used to dry agriculture products because of its effectiveness in drying. To produce partial-parboiled rice using hot-air fluidization technique has been received increasing attention due to simplicity of operation. Thus, the purpose of this work was to investigate the effects of pre-steaming time and drying temperatures on qualities of partial-parboiled rice. The results revealed that head rice yield, pasting temperature and degree of gelatinization increased with an increase in pre-steaming time whereas white belly decreased. The percentage of water uptake of pre-steamed rice decreased with an increase in drying temperature while the percentage of solid loss and stickiness were not affected. The hardness of pre-steamed rice was higher than that of reference rice and it increased with an increase in drying temperature. To obtain the suitable conditions for producing partially-parboiled rice using hot-air fluidization technique, paddy was soaked at temperature of 80 °C for 5 h and then it was blown with saturated steam temperature of 102 °C for 70 s (pre-steaming). After that it was dried using fluidization technique at hot-air temperature of 140 °C for 2 min and then it was tempered for 30 min; furthermore, it was ventilated at ambient air temperature until the final moisture content was approximately 14–16% d.b.     

稻谷水热加工过程中镉迁移规律研究

目的研究稻谷在蒸谷米水热加工过程中镉的迁移规律。方法以蒸谷米小试装置及生产线采集样品为研究对象,在优化碾米时间的基础上,在排除水分含量差异对测定结果的前提下,利用统计分析考察水热工艺(浸泡和蒸煮)对稻谷各部分(稻壳、米糠和精米)镉含量的影响。结果由实验数据推断,在水热过程中,镉的迁移主要发生在稻谷的内部,且主要是在浸泡时从精米向米糠迁移富集,而蒸煮工艺则对镉的分布变化影响很小;经过浸泡,精米中的镉含量可降低约40%;推测热水的浸泡一方面使胚乳淀粉分子间游离的镉部分溶出,一方面促使镉向络合能力更强的米糠蛋白迁移,最终导致其分布发生明显变化。结论该研究为在稻谷加工过程中实现重金属镉的消减提供了科学依据。     

Characteristics of functional brown rice prepared by parboiling and microwave drying

Brown rice (BR) is well known for its functional properties; however, it is considered unsuitable for consumption in modern diet owing to its hard texture, low digestibility, and high lipid peroxidation. In this study, we investigated the physicochemical properties, and cooking and storage characteristics of functional BR prepared by parboiling (100°C, 15 min) and microwave drying (100 kW, 8 rpm, 91°C, 40 min) processes. These processes significantly increased resistant starch (RS) content by 1.5-fold and total dietary fiber (TDF) content by 1.8-fold; Parboiling and microwave drying processes increased the umami taste by 10% using electronic tongue and decreased the hardness by 10% using texture analyzer, respectively. Additionally, irrespective of the storage duration, these processes remarkably decreased acidity and bacterial counts in the parboiled BR group compared to that in the BR group. Presumably, higher RS and TDF contents, enhanced umami taste, and longer shelf-life of BR would help patients with obesity and diabetes, and industries developing relevant high-value food products.     

Vitamin A fortification: Recent advances in encapsulation technologies

Vitamin A is an essential micronutrient whose deficiency is still a major health concern in many regions of the world. It plays an essential role in human growth and development, immunity, and vision, but may also help prevent several other chronic diseases. The total amount of vitamin A in the human diet often falls below the recommended dietary allowance of approximately 900–1000 $\mu$g/day for a healthy adult. Moreover, a significant proportion of vitamin A may be degraded during food processing, storage, and distribution, thereby reducing its bioactivity. Finally, the vitamin A in some foods has a relatively low bioavailability, which further reduces its efficacy. The World Health Organization has recommended fortification of foods and beverages as a safe and cost-effective means of addressing vitamin A deficiency. However, there are several factors that must be overcome before effective fortified foods can be developed, including the low solubility, chemical stability, and bioavailability of this oil-soluble vitamin. Consequently, strategies are required to evenly disperse the vitamin throughout food matrices, to inhibit its chemical degradation, to avoid any adverse interactions with any other food components, to ensure the food is palatable, and to increase its bioavailability. In this review article, we discuss the chemical, physical, and nutritional attributes of vitamin A, its main dietary sources, the factors contributing to its current deficiency, and various strategies to address these deficiencies, including diet diversification, biofortification, and food fortification.     

Status of dietary fiber contents in pigmented and non-pigmented rice varieties before and after parboiling

Five different varieties of paddy (four pigmented and one non-pigmented) were shelled and milled in pre and post parboiled form, their dietary fiber contents were estimated. Under similar conditions of milling, raw rice showed a high degree of polish (DOP), 9–12 g/100 g and parboiled rice showed low DOP, 4.6–6.6 g/100 g. Dietary fiber content was high in pigmented rice, 9–10 g/100 g compared to non-pigmented, ∼6 g/100 g. Soluble fiber content in pigmented head rice (dehusked) varied from 1 to 1.5 g/100 g and in its brokens varied from 0.45 to 1.45 g/100 g. Dietary fiber content was low by about 1% in parboiled rice. In the parboiled rice of pigmented varieties, the total fiber content varied from 7.95 ± 0.15 to 9.05 ± 0.25 g/100 g and the soluble fiber content varied from 0.7 to 0.9 g/100 g. In milled parboiled rice the respective values were 5 ± 0.4 to 6 ± 0.1 g/100 g and 0.85 ± 0.05 to 1.25 ± 0.05 g/100 g. However, the soluble fiber content in the non-pigmented brown rice, IR-64 remained same after parboiling, 0.75 ± 0.5 g/100 g. Milled parboiled rice showed higher soluble dietary fiber compared to milled raw rice. In conclusion, dietary fiber was high in pigmented rice varieties when compared with non-pigmented rice.     

Estimation and fortification of vitamin D3 in pasteurized process cheese

The objective of this study was to develop methods for the estimation and fortification of vitamin D3 in pasteurized Process cheese. Vitamin D3 was estimated using alkaline saponification at 70 degrees C for 30 min, followed by extraction with petroleum ether:diethyl ether (90:10 vol/vol) and HPLC. The retention time for vitamin D3 was approximately 9 min. A standard curve with a correlation coefficient of 0.972 was prepared for quantification of vitamin D3 in unknown samples. In the second phase of the study, pasteurized Process cheeses fortified with commercial water- or fat-dispersible forms of vitamin D3 at a level of 100 IU per serving (28 g) were manufactured. There was no loss of vitamin D3 during Process cheese manufacture, and the vitamin was uniformly distributed. No losses of the vitamin occurred during storage of the fortified cheeses over a 9-mo period at 21 to 29 degrees C and 4 to 6 degrees C. There was an approximately 25 to 30% loss of the vitamin when cheeses were heated for 5 min in an oven maintained at 232 degrees C. Added vitamin D3 did not impart any off flavors to the Process cheeses as determined by sensory analysis. There were no differences between the water- and fat-dispersible forms of the vitamin in the parameters measured in fortified cheeses.     

Concept of double salt fortification; a tool to curtail micronutrient deficiencies and improve human health status

Fortification of food with micronutrients such as vitamins and minerals is one of the main strategies used to combat micronutrient deficiencies. Fortification in common salt is a fruitful strategy because of the daily consumption of 5–12 g salt per person globally. Therefore double fortification of salt with iodine and iron could be a reasonable approach to prevent both iodine and iron deficiencies. It is reckoned that about two billion people are iodine‐deficient worldwide. Iodine deficiency during pregnancy may affect the health status of both mother and fetus and increase infant mortality. Deficiencies of both these micronutrients during childhood affect somatic growth and cognitive and neurological function. Thyroid metabolism is negatively affected by iron deficiency and reduced effectiveness of iodine prophylaxis in areas of endemic goiter. High prevalence of iron deficiency among children may be reduced by the application of effective iodized salt programs. However, ensuring the stability and bioavailability of both iron and iodine as double‐fortified salt is difficult. Iodine present in iodide or iodate form in dual‐fortified salt is oxidized to free iodine in the presence of ferrous ions and oxygen and consequently loses its characteristics. Moreover, ferrous iron is more bioavailable but is readily oxidized to the less bioavailable ferric form. However, both forms of iron may lead to discoloration of the final product, which can be reduced by providing a physical barrier around the iron. Salt encapsulation is one of the best tools to provide a physical barrier for undesirable reactions and interactions during storage. In this review the concept of dual salt fortification, the impact of fortification on curing various life‐threatening maladies, latest assessments of mineral deficiencies and the choice of fortificants are discussed. © 2014 Society of Chemical Industry