Pinky Raigond

Resistant starch in food: a review.

The nutritional property of starch is related to its rate and extent of digestion and absorption in the small intestine. For nutritional purposes, starch is classified as rapidly available, slowly available and resistant starch (RS). The exact underlying mechanism of relative resistance of starch granules is complicated because those factors are often interconnected. The content of RS in food is highly influenced by food preparation manner and processing techniques. Physical or chemical treatments also alter the level of RS in a food. Commercial preparations of RS are now available and can be added to foods as an ingredient for lowering the calorific value and improving textural and organoleptic characteristics along with increasing the amount of dietary fiber. RS has assumed great importance owing to its unique functional properties and health benefits. The beneficial effects of RS include glycemic control and control of fasting plasma triglyceride and cholesterol levels and absorption of minerals. This review attempts to analyze the information published, especially in the recent past, on classification, structure, properties, applications and health benefits of RS.

Translation initiation in plants: roles and implications beyond protein synthesis

Protein synthesis is a ubiquitous and essential process in all organisms, including plants. It is primarily regulated at translation initiation stage which is mediated through a number of translation initiation factors (eIFs). It is now becoming more apparent that in addition to synthesis of proteins, eIFs also regulate various aspects of plant development and their interaction with environment. Translation initiation factors, such as eIF3, eIF4A, eIF4E, eIF4G, and eIF5A affect different processes during vegetative and reproductive growth like embryogenesis, xylogenesis, flowering, sporogenesis, pollen germination, etc. On the contrary, eIF1A, eIF2, eIF4, and eIF5A are associated with interaction of plants with different abiotic stresses, such as high temperature, salinity, oxidative stress, etc. Similarly, eIF4E and eIF4G have roles in interaction with many viruses. Therefore, the translation initiation factors are important candidates for improving plant performance and adaptation. A large number of genes encoding eIFs can functionally be validated and utilized through genetic engineering approaches for better adaptability and performance of plants by inhibiting/minimizing or increasing expression of desired eIF(s).

Key players associated with tuberization in potato: potential candidates for genetic engineering

Abstract Tuberization in potato (Solanum tuberosum L.) is a complex biological phenomenon which is affected by several environmental cues, genetic factors and plant nutrition. Understanding the regulation of tuber induction is essential to devise strategies to improve tuber yield and quality. It is well established that short-day photoperiods promote tuberization, whereas long days and high-temperatures inhibit or delay tuberization. Worldwide research on this complex biological process has yielded information on the important bio-molecules (proteins, RNAs, plant growth regulators) associated with the tuberization process in potato. Key proteins involved in the regulation of tuberization include StSP6A, POTH1, StBEL5, StPHYB, StCONSTANS, Sucrose transporter StSUT4, StSP5G, etc. Biomolecules that become transported from “source to sink” have also been suggested to be important signaling candidates regulating the tuberization process in potatos. Four molecules, namely StSP6A protein, StBEL5 RNA, miR172 and GAs, have been found to be the main candidates acting as mobile signals for tuberization. These biomolecules can be manipulated (overexpressed/inhibited) for improving the tuberization in commercial varieties/cultivars of potato. In this review, information about the genes/proteins and their mechanism of action associated with the tuberization process is discussed.

Potential of Indian potatoes for the management of hyperglycemia

Potatoes are less favoured by health conscious people due to the notion that it has high glycaemic index. Anti-hyperglycemic and antioxidative potential of Indian potato cultivars were evaluated with the aim to remove the misconception. Glycaemic index was measured indirectly through estimating resistant starch, amylose content and activity of α-amylase and α-glucosidase inhibitors from cooked tubers of 46 Indian potato cultivars. The α-glucosidase inhibitory activity ranged from 0 to 52.8% and was observed only in 14 cultivars, viz., Kufri Anand, Kufri Arun, Kufri Khasigaro, Kufri Kuber, Kufri Kundan, Kufri Muthu, Kufri Naveen, Kufri Neela, Kufri Pushkar, Kufri Red, Kufri Sadabahar, Kufri Safed, Kufri Sutlej and Kufri Swarna. α-amylase inhibitory activity was found only in cultivar Kufri Frysona (20.5%). Resistant starch content ranged from 1.22 to 1.93 mg/100 mg DW with highest value in Kufri Garima (1.93 mg/100 mg DW). Amylose content ranged from 10.8 to 27.6 mg/100 mg DW and was the maximum in processing cultivar Kufri Chipsona-3 (27.6 mg/100 mg DW). The highest activities of α-glucosidase inhibitors along with considerable resistant starch content was observed in cultivars, viz. Kufri Kuber, Kufri Khasigaro, Kufri Muthu, Kufri Naveen and Kufri Pushkar. Therefore, these potato cultivars can be used as speciality potatoes as these attributes have potential to prevent hyperglycemia helping manage the incidence of type II diabetes.

Antimicrobial Activity of Potato Starch-Based Active Biodegradable Nanocomposite Films

Food-borne pathogens such as Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) create a lot of problems worldwide and are a major concern of food producers and consumers. To protect the food from spoilage due to these bacteria, antimicrobial packaging is one of the most promising active packaging systems. Environmental concerns associated with plastic waste emphasized the development of packaging films from natural polymers such as starch. Therefore, in the present study, potato starch-based biodegradable and antimicrobial nanocomposite films were prepared with constant concentration of zinc oxide nanoparticles using casting method. Films were prepared using three antimicrobial agents, cinnamon oil, clove oil, and potassium sorbate and were tested against four microbes, S. aureus, E. coli, Salmonella typhi (S. typhi), and Campylobacter jejuni (C. jejuni). The films prepared with clove oil were most effective against S. aureus (22–100% inhibition), those prepared with cinnamon oil were effective against C. jejuni (19–22% inhibition) and growth of E. coli was inhibited (33–40% inhibition) to maximum extent by potassium sorbate incorporated films. However, for complete inhibition of C. jejuni and E. coli, higher concentrations of cinnamon oil and potassium sorbate are required. Increasing concentration of antimicrobial agents decreased the tensile strength of the films. Tensile strength decreased up to 13% in cinnamon oil films, 23% in clove oil films and up to 34% in potassium sorbate incorporated films. Based on the results, it can be concluded that cinnamon oil is a better antimicrobial agent due to its least effect on tensile strength and also due to its antibacterial effect against the three bacteria.

Near-infrared spectroscopy: a non-destructive tool for processing quality evaluation of potatoes

Dry matter and moisture content are two important quality parameters to judge the suitability of any potato cultivar for its ultimate utilization. A non-destructive and rapid method for determination of dry matter (D.M.) and moisture content (M.C.) in potatoes was standardized using near infrared spectrophotometer (NIRSp) system. Training and calibration of the instrument were done using fresh produce of potatoes (year 2014) harvested from Modipuram Campus of ICAR-CPRI whereas, validation of the application was done from fresh produce of same location and 13 advance coloured hybrids from Patna centre of ICAR-CPRI from the year 2015 produce. The predicted values for M.C. and D.M. content using NIRSp were in the range from 76.00 to 83.98 and 16.02 to 24.00% against 75.35 to 86.76 and 14.64 to 24.65%, of wet lab experimental values, respectively. This shows per cent error in M.C. and D.M. prediction vary from 0.86 to 3.20 and 2.70 to 9.43%, respectively. Complete randomization against the horizontal axis shows applicability and accuracy of the prediction through NIRSp developed applications. However, accuracy of prediction can be further enhanced by expanding the training/calibration sample sets. This developed application may be utilized for screening of large number of potato samples like at the time of bulk receiving by the industry, germplasm evaluation, hybrid selection and varietal development etc.

Profiling of Indian potato cultivars for major 5 nucleotides

A field experiment was carried out during kharif, 2012 at Student’s Farm, College of Agriculture, Rajendranagar, Hyderabad wherein the efficacy of seven insecticides viz., emamectin benzoate 5 SG at 11 g a.i.ha, emamectin benzoate 5 SG at 22 g a.i.ha, profenophos 50 EC at 500 g a.i.ha, profenophos 50 EC at 1000 g a.i.ha, spinosad 45 SC at 100 g a.i.ha, bifenthrin 10 EC at 100 g a.i.ha and Bacillus thuringiensis at 5 WP at 25 g a.i.ha were evaluated against Plutella xylostella on cabbage. The dissipation pattern of profenophos 50 EC (1000 g a.i.ha) and bifenthrin 10 EC (100 g a.i.ha) was studied collecting samples at regular intervals i.e. 0, 1, 3, 5, 7, 10, 15 and 20 days after last spray and analyzed at AINP on Pesticide Residues, Rajendranagar, Hyderabad to know the dynamics of degradation. Another set of cabbage samples collected at regular intervals i.e. 0, 5, 10, 15 and 20 days after last spray and analyzed for profenophos and bifenthrin residues after removing top three layers to know the effect of pre harvest risk mitigation method and removal of profenophos and bifenthrin residues by using validated QuEChERS method. Among all the insecticides, profenophos (1000 g a.i.ha) was found to be the most effective one with a maximum reduction in Plutella xylostella population (70.20%), followed by bifenthrin 10 EC at 100 g a.i.ha (68.18%). The initial deposits of 0.99 mg kg profenophos recorded at 2 hours after last spray dissipated to 0.85, 0.82, 0.16 and 0.07 mg kg by 1, 3, 5 and 7 days after last spray, respectively and below determination level (BDL) by 10 day. Based on the dissipation pattern, a safe waiting period of 15 days was recommended taking into consideration of profenophos MRL (0.01 mg kg) given by EU. The initial deposits of 2.24 mg kg bifenthrin recorded at 2 hours after last spray dissipated to 1.72, 1.38, 0.82 and 0.23 mg kg by 1, 3, 5 and 7 days after last spray, respectively and below determination level (BDL) by10 day. Based on the dissipation pattern a safe waiting period of 2 days was recommended taking into consideration of MRL (1.0 mg kg) given by EU and 3 days was recommended based on the MRL (0.4 mg kg) of CAC. The data collected on removal of profenophos and bifenthrin residues in cabbage by removing top three leaves indicate that 91.91 % of profenophos residues and 25.90 % of bifenthrin residues can be eliminated easily.An experiment comprising levels of liming (liming and no liming), potassium application (0, 500 and 1000 g/tree) and shoot age was conducted in the research farm of Indian Institute of Natural Resins and Gums, Ranchi during 2011-12 to 2013-14 replicated five times to study the effect of soil fertility on rangeeni lac yield in the summer season on medium sized trees. Findings of the experiment indicated that lac yield ratio obtained in liming was 71 percent higher compared to no liming in case of 6 months age of shoots. However, analysis of data revealed that liming has got least effect on older shoots. Its effect was also reflected on yield attribute like sticklac yield. Increased soil fertility due to liming might have supplied better nutrition to the host and the host in turn could supply better nutrition to the insect. Lac yield increased significantly (4 to 7 times) if cultivation is done in older shoots. Interaction effect of liming and potassium was found to be significant in case of 6 months old shoots. Effect of potassium application was observed in the absence of liming and the highest dose could increase lac yield 2.8 times than that of control on six months old shoots. Similarly, liming in the absence of potassium application proved to be the best treatment. Applied potassium might have facilitated host to support nutrition of lac insect in a better way which ultimately increased lac yield.Regeneration competence of pseudobulb segments of Coelogyne ovalis, procured from in vitro grown cultures, was assessed in Mitra medium alone and in combinations with PGRs. Juvenility of the tissues, chemical stimulus, and position of the explants (apical/basal) were the key factors in initiating the response. The explants from pseudobulbs (>3cm long) did not regenerate whereas those from younger(<3cm in length) regenerated depending upon their position in the source organ..The response frequency and time taken for the development of plantlets also varied with the growth stimulus. Maximum number of shoots was obtained from the basal segments on medium supplemented with cytokinin to auxin in ratio of 10:5 in BM+BAP(10 mg l+NAA(5 mgl) , 40 plantlets are formed after 14 wks..The apical segments formed shoots only from apical meristem. The shoots rooted in the same nutrient medium and formed .The regenerated plantlets were acclimatized & transfered to pots filled with moss, pinebark, brick and charcoal pieces mixture with 90% survival.