JOURNAL OF FOOD SCIENCE AND TECHNOLOGY ASSOCIATION OF FOOD SCIENTISTS & TECHNOLOGISTS, INDIA ¿VOL. 16 NO. 4 JULY-AUGUST 1979 Editor JOURNAL OF FOOD SCIENCE D. Rajagopal Rao AND TECHNOLOGY Associate Editors V. Sreenivasa Murthy N. Chandrasekhara K. Santhanam K. A. Ranganath M. Kantharaj Urs Volume 16 Number 4 July-August 1979 S. Yunus Ahmed Lakshminarayana Shetty The Journal of Food Science and Technology is a bimonthly publication of the Association of Food Scientists CONTENTS and Technologists, India (AFST) issued in February, April, June, August, Research Papers October and December. Protein, Lipid, Mineral and Trypsin Inhibitor Content in Modified Opaque-2 The Editor assumes no responsibility for Maize (Zea mays L.) 129 the statements and opinions expressed by the contributors. H. O. Gupta, M. L. Lodha, K. Sm, Joginder Singh and S. L. Mehta Manuscripts for publication and books for reviewing in the Journal should be Effect of Reducing and Oxidizing Agents on the Farinograph Characteristics of addressed to the Editor, Journal of Indian Wheats 132 Food Science and Technology, AFST, Central Food Technological Research Maninder Kaur and G. S. Bains Institute, Mysore-570013. The Editor reserves the privilege of editing the manuscript to make it suitable for Characteristics of Enzymatic Hydrolysate of Fababean (Vicia faba Minor) Protein 137 publication in the Journal. P. Chakraborty, F. Bramsnaes and A. N. Bose No part of this Journal can be re­ produced by any body without written Yeast Flora from Must, Fermenting Must and Wines with and Without Spices 143 permission of the Editor. Leena S. Trivedi and S. Ethiraj Correspondence regarding subscriptions and advertisements should be addressed to the Executive Secretary, AFST, Adjuncts in Brewing. U. Tapioca Starch 146 Central Food Technological Research Institute, Mysore-570013, India. Pay­ S. S. Dhamija and D. P. Singh ment may be made by cheque, draft, postal or money order in favour of Exec. Secretary, AFST. Malting Quality of New Varieties of Ragi (Eleusine coracana) 149 N. G. Malleshi and H. S. R. Desikachar Executives of the AFST President Oxidative Rancidity in the Skin and Muscle Lipids of Oil Sardine (Sardinella Dayanand longiceps) 151 Vice-Presidents P. G. Viswanathan Nair, P. D. Antony and K. Gopakumar S. K. Majumder M. Bhatia S. Rajagopalan Sorption Isotherms and Monolayer Moisture Content of Raw Freeze Dried Mutton 155 N. D. Banerjee D. P. At trey and T. R. Sharma G. B. Nadkami Exec. Secretary Antioxidative Roie of Curry (Murraya koenigi) and Betel {Piper betel) Leaves in J. D. Patel Ghee 158 Joint Secretary R. S. Patel and G. S. Rajorhia K. R. Sreekantiah Treasurer Micro organisms in Ice Creams and their Public Health Significance 161 K. Lakshminarayana Rao A. K. Guha, H. N. Das, R. Roy and M. L. Dewan t * Research Notes Antibiotic Resistant Enterobacteria of Mutton 165 D. Vijaya Rao, K. R. Gopala Rao and B. Bhagirath. Microbial Studies on Inpack Processed Chapaties 166 D. Vijaya Rao, R. K. Leela and R. Sankaran Aflatoxin in Groundnut Oil, Groundnut Cake and Hydrogenated Oil in Hapur Market, U.P. 169 Ram Pal, B. K. Varma and D. D. Srivastava Cell Macerating Activity of Fanga! Culture Fluids: Standardisation of Assay Procedure 170 Anil Sharma and Richard Joseph Detection of Pongam Oil Using Acetic Anhydride-Sulphuric Acid Reagent 172 G. Ramakrishna, G. Azeemoddin and S. D. Thirumala Rao Book Reviews 173 Association News 176 research papers Protein, Lipid, Mineral and Trypsin Inhibitor Content m Modified Opaque-2 Maize (Zea mays L.) H. 0. Gupta, M. L. Lodha, K. Sen, Joginder Singh and S. L. Mehta Cereal Research Laboratory and Nuclear Research Laboratory, Indian Agricultural Research Institute, New Delhi-110 012 Manuscript received 12 December 1978; revised 1 May 1979 Protein, lysine, minerals, trypsin inhibitor content and fatty acid composition have been estimated in different grades of modified ‘opaque-2’ maize kerne!. With the increase in kernel vitreosity, protein quality deteriorated, kernel weight increased and the content of various minerals decreased. The decrease was more pronounced for Fc and Mn. Fatty acid composition and trypsin inhibitor activity of modified ‘opaque-2’ did not differ much from that of chalky ‘opaque-2’. In general, protein quality was superior and mineral content was also higher in chalky and modified opaque-2 kernels as compared to normal maize. The nutritional superiority of ‘opaque-2’ maize 100 g was drawn from the kernels of each variety/ protein over normal maize is well documented1-2. More category for chemical analysis and ground to 100 recently breeders are trying to develop varieties with mesh. hard endosperm to overcome the agronomic and For endosperm studies, 25-30 kernels were soaked in acceptability problems associated with chalky ‘opaque-2 ’ distilled water at 4°C for 3 hr. Then the pericarp types. A wide range in kernel opacity is recorded even was removed and endosperm collected after remov­ in the presence of ‘opaque-2’ gene under homozygous ing embryo. Dried endosperms were ground to 100 recessive condition3"5. The present study was under­ mesh. taken with a view to determine nutritional status of Protein and lysine: In whole kernel sample, protein various categories of hard endosperm ‘opaque-2 ’ since (Nx6.25) was estimated by micro-Kjeldahl method6 no such information is available in the literature. The and lysine by colorimetric method7. protein, lysine, oil, minerals, trypsin inhibitor content Minerals: Finely ground samples were digested in and fatty acid composition in various categories of tri-acid mixture (10:1:4, HN03: H2S04: HC104 V/V) modified ‘opaque-2 ’ kernels have been determined and according to Piper8. Iron (Fe), Copper (Cu), Manga­ compared with those of normal and chalky ‘opaque-2’ nese (Mn) and Calcium (Ca) were estimated quantita­ maize. tively by Atomic Absorption Spectrophotometer. Potas­ sium (K) and Phosphorus (P) were estimated quanti­ Materials and Methods tatively by flame photometric9 and colorimetric^ The maize varieties, ‘SO/SN composite’ (modified methods respectively. ‘opaque-2’ with hard endosperm), ‘Shakti opaque-2’ Lipid and fatty acids: Crude fat was extracted by composite’ (chalky) and ‘Vijay’ (normal) used for the Soxhlet extraction method using hexane as a solvent. present investigation were grown under identical agro­ Fatty acid analysis was done by gas-liquid chromato­ nomy. Sample from each variety consisted of kernels graphy after methylation of fatty acids as described by from 15-20 well filled ears, which were controlled Sen et aln. The methyl esters were determined by pollinated. For separating ‘opaque-2’ kernels of SO/SN Shimadzu gas chromatograph having dual column and composite into various categories namely 100 per cent fitted with flame ionization detector and digital inte­ opaque, 75 per cent opaque-25 per cent vitreous, 50 grator. Coiled stainless steel column (3m X4 mm ID) per cent opaque-50 per cent vitreous, 25 per cent opa­ were packed with 10 per cent (by weight) of stabilized que-75 per cent vitreous and nearly normal (0 per cent diethylene glycol succinate coated on Chromosorb P opaque-100 per cent vitreous), the kernels were screened 60/80 mesh solid support. The column, detector and against light. The classification was based on the basis injection port temperatures were held at 175°C, 230°C of relative kernel opacity. A representative sample of and 230°C. The nitrogen (carrier gas) flow rate was 129 ì 30 JOURNAL OF FOOf) SCIENCE AND ÍECHNOLOGY, VOL. Ì6, JULY-AUGÜST 1979 kept at 40 ml/min, air and hydrogen pressure rate, 0.8 protein quality deteriorated steadily. Further increase kg/cm2 and 0.5 kg/cm2 respectively for flame ionization in kernel vitreosity to nearly normal level lowered the detector. Retention time was used to identify fatty protein quality drastically. acids and from peak area obtained by integrator, fatty Mineral composition: The mineral elements play an acid composition was determined. important role in metabolic and regulatory processes13. Trypsin inhibitor activity: Trypsin inhibitor activity Therefore, their concentraticns were determined in was determined according to the methcd of Kakade whole kernel and data are presented in Table 2. The et al12. One trypsin unit is defined as an increase of 0.01 results show that wilh the increase in kernel viireosity absorbance 3/2 (A3/2) units at 280 nm in 20 min per 10 the content of various minerals studied, decreased. ml of reaction mixture. Trypsin inhibitor activity is However, the decrease was more pronounced for Fe defined as the number of trypsin units inhibited (TUI). and Mn. The level of all these minerals was substantially Casein was used as substrate. higher in 0, 25 and 50 per cent vitreous kernel types The data reported are an average of duplicate deter­ as compared to ‘Vijay’ normal. Even in 75 per cent minations which agreed closely. vitreous kernels the level of Fe was 95 per cent higher than in ‘Vijay’ normal. The level of most of the minerals Results and Discussion in chalky ‘opaque-2 ’ kernels (0 per cent vitreous) was Kernel weight, protein and lysine: Results presented either comparable or slightly lower than that of ‘Shakti in Table 1 indicate increase in kernel weight and protein opaque-2’. ‘Shakli opaque-2’ had 62, 116, 383, 52, 26 content with increase in the kernel vitreosity in modified and 123 per cent higher P, K, Fe, Cu, Ca and Mn ‘opaque-2’ maize. Lysine content and chemical scores respectively as compared to ‘Vijay’ normal. The level decreased with the increase in kernel vitreosity. Kernel of all the minerals except Fe in segregating normal was weight of segregating normal (100 per cent vitreous) nearly comparable to that of‘Vijay’ normal. Goodshell14 was 85.7 per cent of the ‘Vijaya’ (normal). Kernel reported that ‘opaque-2’ kernels contain more K than weight of chalky opaque-2 kernels (0 per cent vitreous) normal.