Review Article


Phyto-constituents, Pharmacological Properties and Biotechnological Approaches for Conservation of the Anti-diabetic Functional Food Medicinal Plant Salacia: A Review Note

Majid Bagnazari, Mehdi Saidi, Madhusudhan Mudalabeedu Chandregowda, Harishchandra Sripathy Prakash, Geetha Nagaraja

Applied Food Biotechnology, Vol. 4 No. 1 (2017), , Page 1-10
https://doi.org/10.22037/afb.v4i1.14499

Background and Objective: Genus Salacia L. (Celastraceae) is a woody climbing medicinal plant consisting of about 200 species with many endangered species located throughout the world’s tropical areas. Various parts of the plant as food, functional food additive and tea have been extensively used to treat a variety of ailments like diabetes and obesity as well as inflammatory and skin diseases. The present work reviews the phytochemical properties, pharmacological activities, biotechnological strategy for conservation and safety evaluation of this valuable genus.
Results and Conclusion: More efforts are needed to isolate new phytoconstituents from this important medicinal plant. The  echanism of anti-diabetic action has not been done at molecular and cellular levels, thus the fundamental biological understanding is required for future applications. Though the safety of plant species has been well documented and has been confirmed by many toxicological studies, further toxicity research and clinical trials are
recommended. In order to sustain harvest and conservation, agronomic practices for cultivation have to be developed. Establishment of more efficient protocols for in vitro propagation is necessary too. Approaches like genetic manipulation, hairy root culture, media standardization, and use of inducers/precursors for elevation of secondary metabolite levels could also be attractive.
Conflict of interest: The authors report no conflicts of interest.

Original Article


 

Background and Objective: The current study was undertaken to check in vitro different characteristics of Lactobacillus plantarum as potential probiotic. These characteristics include viability of probiotic and pH during cold storage, tolerance to acid and bile, and antibiotic resistance.
Material and Methods: Samples of yogurt were stored at 4°C and analyzed in time 0, 1, 3, 7, 10 and 14 days of storage. In these periods, probiotic and starter cultures were enumerated and the pH parameter was analyzed.
Results and Conclusion: A gradual decline in pH was noticed throughout the storage. Counting of starter cultures decreased by 0.42 log cycle, and the probiotic's viability decreased by 0.68 log cycle at the end of storage, whereas the probiotic's viability in
the samples subjected to re-pasteurization decreased by 0.30, 0.22 log cycles in the selective and reference media, respectively. The average viable cell counts of Lactobacillus plantarum decreased by 0.76, and 0.28 log cycles after incubation period (3 h) at 37ºC in the simulated gastric juice (pH 2.0 and 3.0), respectively. Generally, probiotic can maintain its viability by 76.672% in (1.0% w v -1) bile. Lactobacillus plantarum was resistant to gentamicin, streptomycin, and vancomycin but susceptible to chloramphenicol, and tetracycline. Depended on these characteristics, Lactobacillus plantarum showed probiotic potential.
Conflict of interest: The authors declare no conflict of interest.

Production and Characterization of Glucoamylase by Aspergillus niger

Soumik Banerjee, Uma Ghosh

Applied Food Biotechnology, Vol. 4 No. 1 (2017), , Page 19-26
https://doi.org/10.22037/afb.v4i1.13261

Background and Objective: Glucoamylase is a potent starch degrading enzyme whose cheap production has been an area of research. Its production by Aspergillus niger in solid-state fermentation was studied using dried garden pea peel as a substrate, which enormously reduced the production cost. The current study intended to produce glucoamylase by a cost-effective strategy and exhaustively characterize the enzyme.
Material and Methods: Garden pea peel was used as a substrate in solid state fermentation by Aspergillus niger for the production of glucoamylase under process parameters. Response surface methodology, a statistical tool for optimization, was applied to setup the experimental design for glucoamylase production. Characterization studies of the enzyme were carried out with temperature, pH, metal salts and elemental composition analysis.
Results and Conclusion: The process parameters were temperature, amount of substrate and time of fermentation. Glucoamylase production was highest in the pH range of 5.4-
6.2, was stable at pH 3.8, and maintained its maximum activity even at 70°C for 30 min. It showed higher catalytic efficiency when incubated with metal ions Fe2+, Cu2+, Mg2+, and Pb2+. Km and Vmax for glucoamylase were 0.387 mg of soluble starch ml-1 and 35.03 U μl-1 min-1, respectively. Glycogen was also used as a substrate, which gave an increased Km by 2.585, whose KI was found to be 0.631. Energy-dispersive X-ray spectroscopy was performed for obtaining composition of the pea peel. C, N, and O were found to be 12.53%, 29.9%, and 55.27% by atomic weights, respectively. Cost- and time-effective production of glucoamylase was achieved by utilizing dried garden pea peel (a vegetable residue) powder as the substrate for production. Its high stability ensures efficient utilization under industrial conditions. This work provides a very good platform for the enzyme immobilization studies and scale up production in future.
Conflict of interest: The authors declare that there is no conflict of interest.

Lactic acid Production with in situ Extraction in Membrane Bioreactor

Hamidreza Ghafouri Taleghani, Ali Asghar Ghoreyshi, Ghasem Najafpour

Applied Food Biotechnology, Vol. 4 No. 1 (2017), , Page 27-34
https://doi.org/10.22037/afb.v4i1.13686

Background and Objective: Lactic acid is widely used in the food, chemical and pharmaceutical industries. The major problems associated with lactic acid production are substrate and end-product inhibition, and by-product formation. Membrane technology
represents one of the most effective processes for lactic acid production. The aim of this work is to increase cell density and lactic acid productivity due to reduced inhibition effect of substrate and product in membrane bioreactor.
Material and Methods: In this work, lactic acid was produced from lactose in membrane bioreactor. A laboratory scale membrane bioreactor was designed and fabricated. Five types of commercial membranes were tested at the same operating conditions (transmembrane pressure: 500 KPa and temperature: 25°C). The effects of initial lactose concentration and dilution rate on biomass growth, lactic acid production and substrate utilization were evaluated.
Results and Conclusion: The high lactose retention of 79% v v-1 and low lactic acid retention of 22% v v-1 were obtained with NF1 membrane; therefore, this membrane was selected for membrane bioreactor. The maximal productivity of 17.1 g l-1 h-1 was obtained
with the lactic acid concentration of 71.5 g l-1 at the dilution rate of 0.24 h−1. The maximum concentration of lactic acid was obtained at the dilution rate of 0.04 h−1. The inhibiting effect of lactic acid was not observed at high initial lactose concentration. The critical lactose concentration at which the cell growth severely hampered was 150 g l-1. This study proved that membrane bioreactor had great advantages such as elimination of substrate and product inhibition, high concentration of process substrate, high cell density,
and high lactic acid productivity.
Conflict of interest: There is no conflict of interest.

Microbial Protein Production from Candida tropicalis ATCC13803 in a Submerged Batch Fermentation Process

Sahar Golaghaiee, Fatemeh Ardestani, Hamid Reza Ghorbani

Applied Food Biotechnology, Vol. 4 No. 1 (2017), , Page 35-42
https://doi.org/10.22037/afb.v4i1.13698

Background and Objective: Microbial protein production can resolve one of the major world challenges, i.e. lack of protein sources. Candida tropicalis growth was investigated to specify a medium to reach the highest cell proliferation and protein production.
Material and Methods: Fractional factorial design and the index of signal to noise ratio were applied for optimization of microbial protein production. Optimization process was conducted based on the experimental results of Taguchi approach designs. Fermentation
was performed at 25oC and the agitation speed of 300 rpm for 70 h. Ammonium sulfate, iron sulfate, glycine and glucose concentrations were considered as process variables. Optimization of the culture medium composition was conducted in order to obtain the highest cell biomass concentration and protein content. Experiment design was performed based on the Taguchi approach and L-16 orthogonal arrays using Qualitek-4 software.
Results and Conclusion: Maximum biomass of 8.72 log (CFU ml-1) was obtained using the optimized medium with 0.3, 0.15, 2 and 80 g l-1 of ammonium sulfate, iron sulfate, glycine and glucose, respectively. Iron sulfate and ammonium sulfate with 41.76% (w w-1) and 35.27% (w w-1) contributions, respectively, were recognized as the main components for cell growth. Glucose and glycine with 17.12% and 5.86% (w w-1) contributions,
respectively, also affected cell production. The highest interaction severity index of +54.16% was observed between glycine and glucose while the least one of +0.43% was recorded for ammonium sulfate and glycine. A deviation of 7% between the highest
predicted cell numbers and the experimented count confirms the suitability of the applied statistical method. High protein content of 52.16% (w w-1) as well as low fat and nucleic acids content suggest that Candida tropicalis is a suitable case for commercial processes.
Conflict of interest: The authors declare that there is no conflict of interest.

Background and Objective: Reduced fat cheese often exhibits poor sensory quality due to the reduction of fat, which plays a critical role in flavor and texture. Therefore, there is the challenge to produce a reduced fat cheese with improved sensory attributes and texture that is also comparable to its full-fat counterpart. The main objective of this research was to investigate the effect of different adjunct starter cultures of Streptococcus thermophilus, Lactococcus helvetius and Lactococcus casei, alone or mixed, on the sensory prperties and volatile flavor compounds of reduced-fat cheddar cheeses (formulated with xanthan gum) and compare them with full-fat cheddar cheese during 75-day ripening.

Materials and Methods: Eight treatments according to completely randomized design with a control cheddar cheese (no adjunct starter cultures) were designed. Extraction of the volatiles was carried out using headspace solid phase microextraction. Identification and quantification of volatile flavor compounds were done by gas chromatography-Mass spectrophotometry and gas chromatography, respectively. The sensory analyses were carried out by the 5-point hedonic scale, using trained panelists.

Results and Conclusion: Among all the flavor compounds, more than 98% of the headspace volatile flavor compounds belonged to aldehydes, ketons, esters, alcohols, and acids. As compared to non-inoculated full-fat control, the use of Streptococcus thermophilus, Lactococcus casei and Lactococcus helveticus as adjunct starter cultures in the reduced fat cheddar cheese formulation increased the amount of volatile flavor compounds and enhanced the sensory attributes. The combination of this mixed culture with the reduced fat cheddar cheese containing xanthan gum as fat replacer is a viable alternative to improve the quality characteristics of reduced-fat cheddar cheese.

Conflict of interest: The authors declare that there is no conflict of interest.

Short Communication


Enrichment of Probiotic Yogurt with Broccoli Sprout Extract and its Effect on Helicobacter pylori

Ali Reza Sadeghi, Rezvan Pourahmad, Marjan Mokhtare

Applied Food Biotechnology, Vol. 4 No. 1 (2017), , Page 53-57
https://doi.org/10.22037/afb.v4i1.13828

Background and Objective: Antibiotic consumption is the main way to cure infection induced by Helicobacter pylori. On the other hand, antibiotics have side effects on human body. So, finding an efficient way to replace antibiotic consumption seems necessary. The aim of this study was to investigate the effect of broccoli sprout extract on the viability of probiotic bacteria and yogurt’s physicochemical properties, and examine the synergistic effect of this extract with probiotics on Helicobacter pylori growth inhibition.
Material and Methods: Four levels of broccoli sprout extract (22.5, 45, 90 and 180 mg ml-1) were prepared and their effect on probiotic yogurt samples was examined. Moreover, their anti- Helicobacter pylori effect was determined.
Results and Conclusion: The research results revealed that Broccoli sprout extract did not have any inhibitory effect on Bifidobacterium lactis and Lactobacillus acidophilus. The variations in acidity of the samples were not significant during storage. A positive correlation was observed between broccoli sprout extract concentration and syneresis. The findings showed the synergistic effect of broccoli sprout extract and probiotics on Helicobacter pylori growth inhibition. Therefore, using broccoli sprout extract and probiotic bacteria, we can produce a yogurt that is effective on the growth inhibition of Helicobacter pylori.
Conflict of interest: The authors declare that there is no conflict of interest.