Effect Of Parboiling Research Articles

Effects of parboiling and infrared radiation drying on the quality of germinated brown rice

This research investigated the physicochemical properties, bioactive compounds, and microstructure of brown rice (BR) and non-parboiled and parboiled germinated brown rice (GBR and PGBR). The GBR and PGBR were treated by sun, hot-air oven, or infrared irradiation (IR) drying. The results showed that IR drying enhanced the bioactive compounds of non-parboiled GBR, including γ-aminobutyric acid, α-tocopherol, and total phenolic compounds, while γ-oryzanol and antioxidant activity were comparable to BR. Meanwhile, IR drying significantly improved the head rice yield (HRY) of PGBR while reducing fissured grains. Parboiling also affected the color values of rice grains, suggesting the diffusion of husk color into endosperm and the formation of brown polymers by the Maillard reaction. In addition, IR drying altered the internal structure of rice grains, resulting in abundant intercellular voids. Specifically, the IR-dried non-parboiled GBR significantly enhanced essential bioactive compounds and improved HRY while maintaining the color of standard BR.

Effect of Parboiling and Drying Pretreatment on the Cooking Time and Quality Attributes of Bambara Groundnut

Bambara groundnut (BGN) was separately parboiled for 45 and 90 min, then, sun-, oven-, or freeze-dried. Untreated BGN served as the control. Cooking, physical, chemical, and sensory characteristics were investigated to assess quality. All parboiled-dried samples cooked significantly (p ≤ .05) faster (43%–86%) than the control. Freeze-dried samples showed significantly (p ≤ .05) higher L* values than their sun- and oven-dried counterparts, irrespective of parboiling time. Sphericity and aspect ratio significantly (p ≤ .05) reduced with all the drying methods, though insignificantly when parboiling was extended from 45 to 90 min. Pretreated BGN had higher protein but lower antinutrient contents. Mineral leaching was minimal at 45 min parboiling. Parboiled-dried BGN cooked samples were generally accepted by the panelists as demonstrated by scores of >6 on a 1–9 Hedonic scale. Combined parboiling and (sun- or oven-) drying presents a practicable strategy for BGN farmers/processors to offer an easy-to-cook product, potentially storable for later food preparation by consumers. Practical applications The study provides a useful strategy to farmers/food industries in their quest to meet the increasing demand of consumers for more convenience foods as opposed to the drudgery associated with the long cooking time of Bambara groundnut. Combined parboiling and drying operations produced Bambara groundnut seeds which cooked 43%–86% faster, and had storable potential for later food preparation. The results from the study may enhance the research efforts in recent times aimed at further promoting the utilization of the crop for better food and nutrition security, particularly in regions where its cultivation is favored.

Effect of parboiling on cooking characteristics of finger millet and foxtail millet

Experiments on parboiling of finger millet (Eleusine coracana) and foxtail millet (Setaria italica) were conducted by soaking at 30, 40, 50, 60 and 70°C and steaming for 10, 15, 20, 25 and 30 min. The parboiled millet grains were shade dried and pearled in a laboratory scale pearler-polisher. The cooking characteristics of these parboiled millet grains were assessed in terms of cooking time, water uptake, swelling index and expansion ratio. In the case of finger millet, the cooking time, water uptake, swelling index and expansion ratio ranged 8-13 min, 1.6-3.7 g/g, 0.98-2.27 and 1.26-1.69, respectively. For foxtail millet these quality parameters ranged 9-13 min, 2.5-4 g/g, 1.32-2.75 and 1.45-2.4, respectively. Soaking at 70 and 60°C and steaming for 20 and 10 min, respectively for finger millet and foxtail millet resulted in better cooking characteristics, viz., water uptake, swelling index and expansion ratio, and lower cooking time.

Effect of parboiling on toxic metal content and nutritional composition of three rice varieties locally produced in Nigeria

Parboiling of rice is a common cooking method and its effect on quality of rice is sparse in the existing literature. The current study was designed to evaluate the effect of parboiling on levels of nutritional components and toxic metals of rice locally produced and consumed in Nigeria. Three varieties of rice were considered and each sample divided into two portions for parboiling and conventional cooking procedures using standard methods. The rice flours were prepared for proximate analysis, amino acid and vitamin profiles using HPLC, while minerals and toxic metals were analyzed by inductively-coupled plasma optical emission spectrometry (ICP-OES). Parboiling significantly (p<0.05) increased ash and fiber contents of the rice samples, whereas, lipids considerably (p<0.05) reduced compared to the unparboiled rice. The levels of some of the essential amino acids, vitamins were significantly reduced by parboiling. Parboiling markedly (p<0.05) reduced levels of aluminium, nickel, chromium and manganese; cadmium, lead and arsenic levels were however increased significantly by parboiling. This study reveals that parboiling may significantly affect components of cooked rice and exert impact that may alter health status. Future studies are suggested to clarify further the effect of parboiling on toxic metals in staple food like rice.

Effect of parboiling on decortication yield of millet grains and phenolic acids and in vitro digestibility of selected millet products

Parboiling is a common method used in rice processing to improve milling yield and physicochemical properties. The current study evaluates parboiling as a pre-treatment step in millet decortication and its impact on phenolic profile and in vitro digestibility of two traditional millet products, steam-cooked couscous and porridge, made from pearl (Pennisetum glaucum) and proso (Panicum miliaceum) millets. Parboiling increased decorticated yield of pearl and proso millet by 37% and 28% respectively. It resulted in significant (P < 0.05) rise in free and bound phenolic contents and DPPH (2,2-diphenyl-1- picrylhydrazyl) radical scavenging activity of the millet products. This method significantly (P < 0.05) changed starch digestion fractions of both products thereby reducing expected glycemic index (eGI) while the in vitro protein digestibility of products decreased by 14–17%. Parboiling could be an effective way to improve millet decortication yield as well as produce millet products with higher phenolic acids antioxidant activity and lower GI.

Effect of parboiling and puffing processes on the physicochemical, functional, optical, pasting, thermal, textural and structural properties of selected Indica rice

The selected Gurjari rice variety was identified as intermediate amylose content (20.52 ± 0.30%) Indica, medium grain size, coarse rice based on physico-chemical characteristics. Changes in the properties of rice on parboiling and puffing process were investigated and reported the statistical differences at p ≤ 0.05. The studied attributes are physico-chemical, functional, textural, pasting, thermal, optical, micro-structural, XRD and FTIR characteristics. Process of puffing has significantly (p ≤ 0.05) increased the dimensional parameters almost twice of original dimension and thus reduced the hardness of puffed rice by eight times. The process of puffing significantly (p ≤ 0.05) reduced the moisture content of puffed rice with the enhancement of five times the surface area with the reduced the bulk density more than nine times. Water absorption index and water solubility index were significantly affected on process of puffing. Puffed rice being a precooked product the pasting time were observed as lowest. The differential scanning calorimetric assessment of Gurjari rice indicated as the selected rice is among the low gelatinization temperature rice. The lighter colored puffed rice with the enhanced level of resistant starch associated with puffed rice improves the functionality of the developed puffed rice to consume directly as ready-to-eat or to be used as ready to use item in the preparation of various functional foods thereof.

Effect of parboiling on phytochemical content, antioxidant activity and physicochemical properties of germinated red rice

In order to improve functional properties and palatability of germinated red rice, this study investigated differences in phytochemicals and physicochemical properties of germinated red rice at 2, 5, 10, 15min of parboiling. Total free phenolic content and antioxidant activity of germinated red rice parboiled for 5 and 15min was higher than that of germinated red rice. Free p-coumaric acid increased from 0.20 to 0.67mg/100g with parboiling time increasing from 5 to 15min. Bound vanillic (0.17-0.27mg/100g) and p-coumaric acid (6.56-8.59mg/100g) had higher levels at 0, 2, or 5min. During 15min of parboiling, color difference (ΔE) increased from 0.58 to 9.09, heat enthalpy (ΔH) decreased from 4.69 to 1.94J/g, and internal structure of rice was destroyed. Overall, parboiling time of less than 5min was suitable to improve the quality of germinated red rice.

Effect of parboiling on minerals and heavy metals of selected Sri Lankan traditional rice varieties grown under organic farming

Tropical Agricultural Research and Extension is a peer-reviewed international scientific journal covering a wide range of subject areas in tropical and subtropical agriculture published quarterly by the Faculty of Agriculture, University of Ruhuna, Sri Lanka. The journal is also available on the Faculty of Agriculture, University of Ruhuna website https://www.agri.ruh.ac.lk/tare/index.htm .

Effect of parboiling on the formation of resistant starch, digestibility and functional properties of rice flour from different varieties grown in Sri Lanka

Hydrothermal treatment used in parboiling could induce formation of novel starch properties having potential food applications. In the current work, functional, digestible and retrogradation properties of flour from non-parboiled and steamed parboiled six rice varieties with high amylose content of around 30% but differing in length and width ratio were investigated and compared. The parboiling process reduced swelling volume and amylose leaching in all tested varieties. Among the varieties studied, the resistant starch content ranged from 1.6% in AT 306 to 0.46% in BG 357. Parboiling reduced the resistant starch content in AT 306 by about 50%, but it did not significantly affect the resistant starch content of the other varieties. The amylose-lipid complex remained unchanged after parboiling. Amylopectin retrogradation was not observed in parboiled rice. Amylose retrogradation was not seen except for AT 306. Pasting behaviour of parboiled rice flours showed high pasting stability and low setback. Flours were more susceptible to enzymatic hydrolysis after parboiling. Partial gelatinisation during parboiling was sufficient to produce grains with excellent milling quality showing a head rice recovery that ranged from 98% to 100% among the varieties studied. Degree of gelatinisation is the most important factor that determines the high head rice recovery. High pasting stability and low setback of flour of parboiled rice indicate some potential food applications.

Effect of parboiling on physical and chemical characteristics and non-enzymatic browning of emmer (Triticum dicoccon Schrank)

Parboiling is a popular technology applied to rice to increase its milling yield, nutritional value and resistance to spoilage by insects and mould. This process was applied to Triticum dicoccon Schrank to induce physical, chemical and organoleptic modifications in order to increase its use and product diversification.Hulled and dehulled emmer samples, subjected to different parboiling conditions, were characterized by analyzing the physical and chemical modifications and the non enzymatic browning.The results showed that although parboiled grains were darker than the untreated reference sample, due to the development of non-enzymatic browning and the diffusion of the pigments contained in the husk and bran, during hydrothermal treatment glumes have a protective action on the caryopsis integrity and against thermal damage.

Effects of parboiling and fluidized bed drying on the physicochemical properties of germinated brown rice

Summary Changes in physicochemical properties of germinated brown rice (GBR) and parboiled germinated brown rice (PGBR) dried in a fluidized bed dryer at 110–150 °C were investigated. Results indicated that parboiling altered the properties of GBR owing to starch gelatinisation. The moisture content, yellowness, peak viscosity and hardness of PGBR increased, but internal fissured kernel, cooking time, water absorption and total solids loss decreased when compared to GBR. γ-aminobutyric acid (GABA) content in GBR was 23.31 mg per 100 g and was reduced to 17.91 mg per 100 g in PGBR. The drying times required to reduce the moisture content of GBR and PGBR to 16% d.b. were 4.01–7.65 min and 5.11–9.50 min, respectively. Final moisture content, which is optimum to prevent internal fissures of dried GBR and PGBR, was 27–29% and 25–28% d.b., respectively. The same trend was observed in the physicochemical properties of GBR and PGBR when increasing drying temperature and time.

Effects of parboiling, storage and cooking on the levels of tocopherols, tocotrienols and γ-oryzanol in brown rice (Oryza sativa L.)

Vitamin E and γ-oryzanol display a wide range of biological activities including hypocholesterolemic, anti-inflammatory and antioxidant activities. Although white rice is far more popular worldwide, consumption of brown rice is increasing, partially on account of the presence of bioactive compounds; however, the effects of parboiling, storage and cooking on them are not well-characterized. The effects of parboiling and a 6-month storage period on the contents of vitamin E and γ-oryzanol in three brown rice cultivars grown in three different locations in Brazil were investigated. Also, their levels in branded non-parboiled and parboiled brown rice were monitored before and after cooking. Vitamin E homologues and γ-oryzanol were separated by RP-HPLC equipped with PDA and fluorescence detectors. The average levels of total tocols and γ-oryzanol in the raw brown rice cultivars studied were 25 and 188mg/kg, respectively. Of the vitamin E homologues, γ-tocotrienol contributed with 74% of total tocols, followed by α-tocopherol, α-tocotrienol and γ-tocopherol in minor quantities. The combined processes, parboiling, storage and cooking, led to an approximate 90% reduction in tocols and only γ-tocotrienol was detectable after any of the processes. Parboiling followed by storage resulted in an approximate 40% loss of γ-oryzanol. Cooking had almost no further effect over γ-oryzanol levels in parboiled rice previously stored for 6months.

Effect of parboiling and bran removal on aflatoxin levels in Sri Lankan rice

Commercial parboiling of rice in Sri Lanka and many south Asian countries provides ideal conditions for the occurrence of aflatoxins because the rice is steeped (allowing fermentation) thus providing ideal conditions for growth of toxigenic Aspergillus species. However the traditional 'cottage' method of parboiling rice, which does not involve steeping, appears to reduce Aspergillus growth even after long storage periods. Preferential infection of parboiled rice by Aspergillus flavus was observed. Aflatoxin contents in inoculated rice produced by commercial parboiling (AFB1 60-92 mg/kg) were significantly higher than that in inoculated 'cottage' processed rice (AFB1 12-29 micrograms/kg). The steeping (precooking/soaking) process in commercial parboiling appears to increase the susceptibility of rice grains to fungal infection. Aflatoxin content in grains increased considerably with the increase in duration of soaking. However, the addition of 10 ppm calcium hypochlorite (bleach) to soaking water appreciably reduced A. flavus contamination and subsequent aflatoxin content in parboiled rice. No significant reduction in aflatoxin levels were observed after bran removal of contaminated rice.

Parboiled sorghum: Development of a novel decorticated product

The effect of parboiling on the milling yield and cooking quality of whole sorghum ( Sorghum bicolor [L. Moench]) kernels was examined. Cultivars differing widely in kernel characteristics were: (1) soaked overnight and boiled for 10 min (Soak-Boil or SB) and (2) brought to boiling point, soaked overnight and brought to boil again (Boil-Soak-Boil or BSB). The cooked samples were dried at ambient temperature prior to abrasive decortication. Both parboiling procedures significantly increased the yield of decorticated grain while reducing kernel breakage. The BSB process resulted in significantly higher decorticated grain yields with less ‘brokens’ than the SB process. The decortication yield of soft cultivars was increased by up to 2·2-fold by parboiling, compared with 1·2-fold for hard cultivars. Parboiled, decorticated sorghum produced a light-colored, cooked product with firm, intact kernels and acceptable appearance and aroma. Field trials in Mali with local sorghum and millet samples confirmed the improved decortication yields obtained under laboratory conditions. The cooked products were consumed with Malian dishes and condiments such as peanut sauce and were rated very acceptable. The process requires low-level technology that is available in villages in sorghum and millet producing areas. No specialized equipment is needed to parboil grain on a village scale. Parboiling may be a practical method by which shelf stable, processed products from sorghum and millet can be prepared while enhancing decortication yields, especially for soft cultivars.

EFFECT OF PARBOILING AND FREEZING ON QUALITY OF THREE SPANISH RICE VARIETIES

The effects of parboiling and of freezing at −18, −40°C or in liquid nitrogen on quality of cooked rice was studied for three Spanish varieties, Bahia, Sequial and Italpatna, using instrumental and sensory measurements. Parboiling prior to cooking and then freezing reduced rice quality. Freshly cooked samples differed from frozen cooked samples for firmness as measured instrumentally but not for any of the sensory parameters. Principal component analysis did not separate samples on the basis of their varietal quality.

Effect of parboiling on texture and flavor components of cooked rice

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of parboiling on texture and flavor components of cooked riceHiromichi Kato, Takeo Ohta, Takashi Tsugita, and Yukio HosakaCite this: J. Agric. Food Chem. 1983, 31, 4, 818–823Publication Date (Print):July 1, 1983Publication History Published online1 May 2002Published inissue 1 July 1983https://doi.org/10.1021/jf00118a035RIGHTS & PERMISSIONSArticle Views486Altmetric-Citations38LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (725 KB) Get e-Alerts Get e-Alerts

Distribution of oil in the bran layers of slender, medium, and short grain varieties of rice, and effect of parboiling

AbstractA study of the distribution of oil in slender (IR‐22), medium (Jaya), and short (Bala) grain types of rice indicated that the oil content of the bran was highest in IR‐22 (24.4%) followed by Jaya (22.8%) and Bala (15.2%) at a given (5%) polish percentage. Parboiling increased the oil yield of the bran in all the varieties, but much more in Jaya and Bala (7–9%) than in IR‐22 (3%) indicating that in the slender IR‐22, the oil was more concentrated in the surface layers of the grain. The oil content increased somewhat sharply in IR‐22 and Bala up to 4.0 and 5.5% polish, respectively, and then declined with further polish. In Jaya, the increase was smaller and more or less constant up to 6.0% polish. Changes due to parboiling were similar to those for raw samples with higher values for the parboiled samples. Distribution in surface fractions showed highest values for each fraction from the slender IR‐22 followed by the medium Jaya and the short grain Bala. The pattern of distribution was, however, strikingly different in the slender variety compared to the others. Difference between raw and parboiled fractions in each variety was not similar: in IR‐22, the increase in parboiled samples was 5–7%, 5–13% in Jaya, and as much as 1–11% in Bala.

Effect of parboiling on thiamin, protein and fat of rice.

AbstractParboiling decreased the thiamin content of rice. Nevertheless, milled parboiled rice contained more thiamin than milled raw rice at the same degree of milling because parboiling caused thiamin to diffuse inwardly. Both the degree of loss and the degree of diffusion depended on the severity of the heat treatment. Bran‐polish of parboiled rice had a higher fat and protein content than bran‐polish of raw rice at the same degree of milling because the starchy endosperm of parboiled rice had a greater resistance to milling and so the bran and the germ were more effectively removed. Milled parboiled rice tended to have lower protein content than milled raw rice. Starch content was lower in bran‐polish from parboiled rice.

Effects of Parboiling and Physico-Chemical Characteristics of Rice on the Glycemic and Insulinemic Indices in Type 2 Diabetic Subjects

Background and Purposes: To observe the influence of parboiling, amylose content and gelatinization temperature of rice on plasma glucose and insulin responses in type 2 diabetic subjects because diabetic subjects are especially prescribed usage of starchy foods with low glycemic responses. Methods: Seventeen type 2 diabetic subjects ingested five test meals of 50g available carbohydrate as white bread, cooked rice with high (29%) and low amylose content (13%), undergoing different processing and gelatinization temperatures. The diets were taken in a random order after a 10h overnight fast with approximately 7 days interval as wash out period. Results: The glycemic index (GI) of all rice varieties were lower than that of white bread (p&lt;0.001). Furthermore, GI of parboiled rice with a high amylose content was lower than that of parboiled low amylose rice (50±7 vs 71±5, p &lt;0.01). No differences were observed between parboiled rice with high and low gelatinization temperature (50±7 vs 47± 4), nor between non-parboiled and parboiled rice (52±7 vs 50±7). Insulin responses to the five test foods did not differ significantly in the study subjects. Conclusions: In type 2 diabetic subjects the investigated rices were all low glycemic as compared to white bread, independent of parboiling and physico-chemical characteristics. The study showed that the amylose content, but not the gelatinization temperature, may be an useful criteria in selection of low GI rices irrespective of parboiling status. Ibrahim Med. Coll. J. 2008; 2(1): 12-16 Key words: Amylose, blood glucose, insulin, type 2 diabetes, parboiled rice. doi: 10.3329/imcj.v2i1.2925

The Effect of Parboiling and Milling on the Antineuritic Vitamin (B1) and Phosphate Content of Rice

1. Highly milled parboiled rice was found to be rich in the antineuritic vitamin B1, while roughly milled raw rice was deficient. In estimating the content of vitamin B1 the method of Chick and Roscoe was used.2. Exact comparison was made of the vitamin B1 potency of two samples of rice, the one raw, the other parboiled, after similar degrees of milling. The vitamin value of the unmilled samples was equal, but when each was highly milled to an equal degree, as judged by weight of polishings removed in a hand rice mill, the parboiled sample retained the vitamin while the raw sample did not.3. Polishings from parboiled rice were found to contain less vitamin B1 than those from raw rice.4. Parboiled rice contains more P2O5 than raw rice milled to the same degree.5. It is probable that when rice is steamed in the process of parboiling, the vitamin B1 and some of the phosphate contained in the germ and pericarp diffuse through the endosperm.6. The P2O5 content of raw rice is a good index of vitamin B1 value, but in parboiled rice a low percentage of phosphate is compatible with the presence of the vitamin.Thanks are due to Miss L. M. B. Patterson who kindly made the phosphate estimations recorded in the paper. I am indebted to the Director of Agriculture, British Guiana, for a number of rice samples. The rice mill used was kindly lent by Jackson and Son, 30, Mincing Lane, E.C. 3. I am grateful to Miss Chick for her continued interest in these experiments.