Lac Resin Research Articles

Microwave-assisted extraction and purification of aleuritic acid from seedlac: A fast, eco-friendly and cost-effective single process for enhanced yield and purity

Aleuritic acid is one of the high-value constituents of lac resin, which has a massive demand in the perfumery industry for synthesizing macrocyclic lactones. The commercial aleuritic acid extraction process is lengthy, inefficient, and produces low-quality aleuritic acid, which necessitates repeated purification using toxic chemicals, bleaching agents, organic solvents, and activated carbon to obtain the desired quality aleuritic acid. This study developed a single process for extraction and purification of aleuritic acid involving microwave-assisted hydrolyzing of the seed lac and removing impurities of lac resin through condensation and alkali heat treatment. The novel process has reduced the overall extraction time from 15 days to 1.5–2 days and increases the yield from 35 to 40 % to 85–86 % and purity from 70 to 86 % to > 98 % in a single process without the use of toxic chemicals, bleaching agents, or organic solvents, unlike the commercially available process. HPLC, FT-IR, DSC, and FESEM techniques were employed to characterize and evaluate the quality of the extracted aleuritic acid. The developed process is highly efficient and cost-effective and offers scalable and fast extraction while requiring minimal chemicals, labor, and energy compared to alternative processes. Moreover, it exhibits greater environmental sustainability.

Molten Shellac Resin Mix with Soil Could Be Useful in Crop Protection Modelled With Chick Pea

Rural Society produce has great economic viability that needs to be explored to help improve their income. Plant and insect resins that form a major produce from rural background in India could be explored for further use that can increase their value. In this article we demonstrate the insect resin lac could be used in crop protection since addition of it to soil followed by water retention and plant injury protected Chick pea seedlings as compared to control. In this article we show it for the first time that molten hot shellac (1:25parts) mixed with organic manure used for seed germination conferred protection to seedlings against water logging and water deficit related decay, recovery from physical injury. The basis of protection could be lac altering the dielectric nature of soil, it altering the soil texture or directly inhibiting fungal mycelium responsible for root rot. In water logged condition or drought, root rot fungi could play a major role in destruction of crop. To observe the protection conferred by lac resin, non-pathogenic agaricus fungi was modelled for observing mycelial spread over tin metal plate.

Recovery of Lac Resin from the Aqueous Effluent of Shellac Industry

Shellac and aleuritic acid manufacturing industries generate a lot of alkaline aqueous effluent during the process of manufacture of shellac and aleuritic acid from the seedlac/sticklac. The generated effluent contains lac resin, lac wax, lac dye and other water-soluble organic acids. Shellac industries in India face problems with the disposal of aqueous effluent due to the presence of considerable amounts of natural organic molecules and the dark colour solution. To address these problems, we have developed a novel method for the selective recovery of the lac resin from the alkaline aqueous effluent of shellac manufacturing industry. The recovered lac resin has been characterized by 13C-NMR, FT-IR and melting point and the data were compared with standard industrial-grade resin. The recovered lac resin was evaluated by the lac manufacturing industry for commercial applications.

Investigation of Gold Gilding Materials and Techniques Applied in the Murals of Kizil Grottoes, Xinjiang, China

The present work reports the identification of inorganic and organic materials applied in gildings of Kizil Grottoes mural paintings, located in the western part of China. A total of 10 gold gilding samples were collected from caves dated in the fourth–seventh century AD. In this research, optical microscopy, scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX), UV fluorescence microscopy, and pyrolysis gas chromatography–mass spectrometry (Py-GC/MS) analyses were carried out to clarify the mordant materials and the coating materials on the foils. This research reports some new finds of the gilding technique in Kizil grottoes, such as oil and lac resin being used as mordant to provide a binding medium for gold gilding, gold powder probably being used as pigment, and some organic dyes being well preserved under gold foil. These interesting findings not only provide scientific evidence for us to understand the materials and techniques of gold gildings on Kizil Grottoes murals, but also illustrate material trade and technique exchanges along the Silk Road in the past.

SSH reveals different functional categories of putative resin synthesizing genes in the industrial insect, Kerria lacca (Kerr)

• SSH library was constructed by using crawler and female cDNA as driver and tester, respectively. • Genes of terpene biosynthesis, fatty acid biosynthesis and transcriptional regulation were present in the SSH library. • Decaprenyl diphosphate synthase and acyl-CoA delta desaturase were cloned from lac insects. • Their expression levels in lac insects were also found to be correlated with resin synthesis. Biosynthesis mechanism of the only animal resin, lac resin remains elusive to the scientific community. An attempt to identify the genes of resin biosynthesis in lac insects was made through SSH (Suppression Subtraction Hybridization) library by subtracting genes of resin non secreting stage (neonate nymphs) from the resin secreting stage (adult female) of the lac insect. SSH library yielded 107 non redundant clones with 61 clones having sequences homologous with known functions (defence, development, metabolism, regulation, transport, cell division, respiration, structural role), 7 clones having hypothetical proteins or uncharacterized proteins and 39 clones did not find any matches. Among the differentially expressed genes, few putative genes of terpene biosynthesis, fatty acid biosynthesis and transcriptional regulation were identified. Out of them, an IDS (Isopentenyl Diphosphate Synthase) type decaprenyl diphosphate synthase and a desaturase gene, acyl-CoA delta desaturase were cloned from lac insects and sequenced. Their expression levels were found to be more in lac resin synthesis stages such as settled nymphs and fertilized female insects in comparison with resin non secreting stage, crawlers (neonate nymphs). It gives a clear indication of their role in lac resin biosynthesis due to the correlation of their expression level with resin biosynthesis in lac insects.

Preparation and Performance of Thermochromic and Self-Repairing Dual Function Paint Film with Lac Resin Microcapsules and Fluorane Microcapsules.

Microcapsules with lac resin as the core material and urea-formaldehyde resin as the wall material were prepared by in situ polymerization, and then the lac resin microcapsules and fluorane microcapsules were added into a water-based primer or topcoat, respectively, to prepare water-based coatings with dual functions of thermochromic and self-repair. The effects of different methods of adding microcapsules on the optical properties, mechanical properties, self-repairing properties, and the aging resistance of water-based paint film were investigated, so as to prepare water-based paint film with the best discoloration and self-repairing functions. The results showed that the paint film with 10.0% fluorane microcapsules in the topcoat and 5.0% lac resin microcapsules in the primer had better comprehensive properties, and the paint film changed from yellow to colorless at 32 °C, with a color difference of 68.9, hardness of 3H, adhesion grade of 0, impact resistance of 13.0 kg∙cm, and elongation at break of 20.0%. The resistance of the paint film to NaCl, ethanol, and detergent was grade 2, with slight discontinuous marks, and the resistance to red ink was grade 3, with slight marks. The lac resin microcapsules have good aging resistance, which can enhance the aging resistance of the paint film with fluorane microcapsules. The gap width of the paint film was repaired by 2.1 µm, the self-repairing rate was 12.3%, and the paint film with lac resin microcapsules had a better crack inhibition effect. The results have provided a reference for multifunctional wood coatings.

​Pigeon Pea [Cajanus cajan (L.)]: New Promising Host of Lac [Kerria lacca (Kerr)] in Southern Rajasthan

Background: Lac is a resin secretion of insects [Kerria lacca (Kerr)], which are commercially cultivated through ages. Lac cultivation has its roots in India and a major source of economy to the local populace. Though different lac hosts have been recorded in Rajasthan, but it is not cultivated commercially. Pigeonpea crop could be utilized for encouraging lac cultivation in the region and yield losses can be compensated by additional income received from lac resin. Methods: The experiment on “Studies on Economics and Yield Attributing Parameters of Lac Cultivation on Yield of Pigeonpea, Cajanus cajan (L.) in Southern Rajasthan” was conducted on Rangeeni strain of lac insect in Baisakhi season at lac insect gene bank cum garden situated at Department of Entomology, Rajasthan College of Agriculture, MPUAT, Udaipur during 2019-20 and 2020-21 respectively. The life cycle of Rangeeni strain of lac insect were studied on pigeonpea sown in last week of August in plot size measuring 2 × 10 sq m during Baisakhi season of both year. Result: The study revealed that the mean initial settlement density of lac insect on pigeonpea ranged from 67.53 to 84.20 with 4.27 to 5.27 (per sq. cm) mature female cell density during successive years. The mean per cent settlement was found to be the maximum (91.78 and 91.15%) at lower portion of the pigeonpea plant during respective years. The duration of sex differentiation ranged from 48.23 to 49.10 days for both successive years. The benefit cost ratio was also higher (1.95 and 2.09) in lac inoculated experiment then the sole seed crop (control) of pigeon pea (1.84 and 1.35) in season 2019-20 and 2020-21, respectively. All the parameter revealed that pigeon pea is economically efficient host for the Rangeeni strain of lac in agro-climatic region of southern Rajasthan.

Equipments for Manufacturing Lac Based Value Added Products

Lac, a natural resin of insect origin, yields basically three useful materials i.e.resin, wax and dye and is an important source of livelihood for poor and tribal farmers in the lac growing regions. Lac growers harvest lac in form of lac stick and lac encrustations attached with sticks are then scraped which is known as sticklac. Sticklac contains impurities which need to be removed by converting sticklac in to seedlac through different unit operations under primary lac processing so that seedlac, a semi-refined product, can be further used in making lac based value added products i.e.shellac, button lac, bleached lac, aleuritic acid etc. Sticklac converted into seedlac can be stored like grain in jute/gunny bag or metal bin for longer period. Hence, lac grower can sell stored seedlac whenever they get remunerative price. Lac resin being natural, biodegradable and non-toxic, finds application in food, textile, furniture, electrical and pharmaceutical industries and provides immense employment opportunities. Regular demand for the materials derived from lac exists in the market due to global trend for use of natural products. Small scale lac processing unit can be established for conversion of sticklac in to seedlac in production catchment area at grower's level itself. Similarly, integrated small scale lac processing unit can also be utilized for conversion of sticklac in to seedlac with reduced man-power requirement and minimum drudgery. Equipments/machineries developed for manufacturing value added lac-based products may be encouraged in the country to reduce time of operation, drudgery and manpower requirement with enhanced capacity of value addition in lac and to promote entrepreneurship development which may further enhance employment generation. To ensure the quality of produce, traditional equipments/machineries needs replacement with new equipments/machineries made of food grade materials coupled with advanced automation system to the maximum possible extent. Value addition in lac could be promoted and migration of rural and tribal people to other states in search of employment could be minimized with adoption of improved equipment and machineries for value addition of lac at village level so that rural and tribal people may get remunerative price of their product. Hence, increase in sustainable livelihood of rural and tribal people might be possible with adoption of lac value addition sector

REDUCTION OF OIL UPTAKE FROM POTATO FENCH FRIES BY PLASTICISER SHELLAC AND ULTRASOUND TECHNOLOGY

Edible lac resin, shellac in different concentrations was used as a coating agent to reduce the oil uptake in deep-fried potato fries. The coating formulation was carried out by Shellac and D-Sorbitol. Shellac used in the concentrations 0%, 1%, 2%, 3%, 4% and 5% in combination with 0.25% D-sorbitol. Further coated samples were treated with ultrasonication for 5 minute and 10 minutes at 50 Hz. Potato fries coated with shellac and ultrasonicated were deep fried and analyzed for oil uptake, moisture content, color and sensory analysis. The oil content and moisture content of deep fried potato fries were determined using standard AOAC method, the colour analysis was carried out by software-based application and sensory analysis was carried out by a 9 point hedonic scale by 30 untrained panelists. With the increase in the concentration of shellac, the oil uptake by potato fries significantly reduced showing the highest reduction of 54.24% in 5% shellac coated potato fries. Potato fries coated with 5% shellac and ultrasonicated for 5 minutes showed 55.07% reduction whereas at 10 minutes, it showes reduction of 57.87%.

Identification of Organic Materials Used in Gilding Technique in Wall Paintings of Kizil Grottoes

AbstractRed and yellow organic resinous layers were observed beneath the foil decoration of Cave 171 (5th‐7th Century A.D.) in Kizil Grottoes, the earliest Buddhist grottoes in ancient Central Asia. Liquid chromatography‐mass spectroscopy and pyrolysis gas chromatography‐mass spectroscopy results demonstrated the presence of lac resin and typical pyrolysis of drying oil. In order to overcome the difficulties in confirming the organic materials in different gilding layers, micro‐Fourier transform infrared spectroscopy (μ‐FTIR) and desorption electrospray ionization‐mass spectrometry (DESI‐MS) scanning were performed on the painting cross‐section. High contents of di‐carboxylic acids, which are the typical markers of degraded drying oil, are detected in the upper yellow layer and lower red ground, indicating the drying oil was mixed with minium (Pb3O4) as binder for preparing the substrate as well as the mordant for gilding, and lac resin was painted over minium as the background color.

Investigation of gilding materials and techniques in wall paintings of Kizil Grottoes

The present work reports the new characterization results of the gilding materials used in Cave 171 of Kizil Grottoes, China, which is dated between 5th and 7th Century, A.D. Tiny samples collected from four different gilding decorations were analyzed by scanning electron microscopy with element energy dispersive X-ray spectroscopy (SEM-EDS) to identify the gilding structure and inorganic materials. It was discovered that both tin and gold leaves were used as the gilding foils. Interestingly, different organic mordants were used under different foils. The pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) results show that drying oil was applied as the mordant for the adhesion of tin foils while lac resin was used for gold foils. The presence of lac resin has been further confirmed by liquid chromatography-electron spray ionization-mass spectrometry (LC-ESI-MS). Although lac dye has been detected as the red colorant in wall paintings of Buddhist grottoes, its use as gilding mordant is a new finding. These gilding materials found in the wall paintings of Kizil Grottoes may provide some evidence of painting materials and techniques exchange along the Silk Road.

Traditional Cultivation Of Laccifer lacca Kerr. in Alor, East Nusa Tenggara

Lac is a resin produced by secretion of small insect of Laccifer lacca in Kesambi trees. Lac resin is important for paint, ink, pharmacy, cosmetic, electricity, coating (candy, fruits, and vegetables), textile and candle industries. Lac price in the market is IDR 10,000.00/kg in 2019, while the lac price in 2005 – 2006 was IDR 60,000.00/kg. The decrease of lac price in Alor Island due to lack of technology in increasing the lac quantity, quality and no special institution to facilitate lac marketing. The objective of this survey was to study the traditional practices of lac cultivation in Alor Island. The method was done by field survey in the farmer gardens and interviewed the farmers. The result showed that lac cultivation in Alor Island is done traditionally and low technological inputs. Insect inoculation is done on young branches at 1 m above ground of 16 years old of Kesambi trees as a host. The maintenance of Kesambi trees is done by cutting old branches. Lac harvesting is done in June, July and in December by cutting the colonized branches into small size, and dried under sunlight. Lac resin is crushed into granular sizes, and packed into plastic bags for post-harvesting technology.

Influence of Coating Developed from Oligomer Isolated from Lac Resin on Post-Harvest Quality and Shelf Life of Peaches (Prunus Persica L.)

Influence of Coating Developed from Oligomer Isolated from Lac Resin on Post-Harvest Quality and Shelf Life of Peaches (Prunus Persica L.)

Influence of coating developed from oligomer isolated from lac resin on post-harvest quality and shelf life of peaches (Prunuspersica L.)

Influence of coating developed from oligomer isolated from lac resin on post-harvest quality and shelf life of peaches (Prunuspersica L.)

Structural identification and biological activity of six new Shellolic esters from Lac

Six new sesquiterpenoid esters, named Shellolic ester A–F (1–6), along with four known Lac dyes (7–10) were isolated from methanol extract of the secretions of Laccifer lacca. Their structures were established on the basis of spectroscopic analyses (IR, HR-ESI-MS, 1D and 2D NMR) and by comparison with published data. Biological activities evaluation of the isolates showed that they were inactive against human cancer cell lines (HepG2, MCF-7, Hela and C6) and LPS-treated RAW264.7, which is well consistent with that Lac resin used as nontoxic material in agriculture applications, pharmaceutical formulations, and food additives. However, compound 2, 4, 7, 9, 10 were found to be considerable active against B. subtilis, E. coli, and S. aureus microorganisms. The results complements the current knowledge about Lac produced from China. Meanwhile, Our present study further reveals that Lac resin are edible with no toxicity and physiologically harmless at the level employed as an excipient.

Biodegradable polyester films from renewable aleuritic acid: surface modifications induced by melt-polycondensation in air

Good water barrier properties and biocompatibility of long-chain biopolyesters like cutin and suberin have inspired the design of synthetic mimetic materials. Most of these biopolymers are made from esterified mid-chain functionalized ω-long chain hydroxyacids. Aleuritic (9,10,16-trihydroxypalmitic) acid is such a polyhydroxylated fatty acid and is also the major constituent of natural lac resin, a relatively abundant and renewable resource. Insoluble and thermostable films have been prepared from aleuritic acid by melt-condensation polymerization in air without catalysts, an easy and attractive procedure for large scale production. Intended to be used as a protective coating, the barrier's performance is expected to be conditioned by physical and chemical modifications induced by oxygen on the air-exposed side. Hence, the chemical composition, texture, mechanical behavior, hydrophobicity, chemical resistance and biodegradation of the film surface have been studied by attenuated total reflection–Fourier transform infrared spectroscopy (ATR–FTIR), atomic force microscopy (AFM), nanoindentation and water contact angle (WCA). It has been demonstrated that the occurrence of side oxidation reactions conditions the surface physical and chemical properties of these polyhydroxyester films. Additionally, the addition of palmitic acid to reduce the presence of hydrophilic free hydroxyl groups was found to have a strong influence on these parameters.

Identification of genes related to resin biosynthesis in the Indian lac insect, Kerria lacca (Hemiptera: Tachardiidae)

Kerria lacca (Kerr) is commercially harnessed for lac resin, which is principally an ester complex of aleuritic acid (9,10,16-trihydroxyhexadecanoic acid) and jalaric acid. The present study is an attempt made to identify the possible pathways involved in the biosynthesis of lac resin. It is proposed that acetyl-CoA is the common precursor for the biosynthesis of aleuritic acid and sesquiterpenic acids (jalaric acid). Prenyltransferases are involved in the biosynthesis of sesquiterpenes; hydroxylation of hexadecanoic acid, after chain elongation, appears to occur through the action of cytochrome P450 enzymes. Two related genes as proposed above were identified and sequenced. The diurnal rhythm of resin secretion and protein concentrations were also studied and correlated for ascertaining the active secretory phase.

Characterisation and discrimination of various types of lac resin using gas chromatography mass spectrometry techniques with quaternary ammonium reagents

A variety of lac resin samples obtained from artists’ suppliers, industrial manufacturers, and museum collections were analysed using gas chromatography mass spectrometry (GCMS) and reactive pyrolysis GCMS with quaternary ammonium reagents. These techniques allowed a detailed chemical characterisation of microgram-sized samples, based on the detection and identification of derivatives of the hydroxy aliphatic and cyclic (sesquiterpene) acids that compose the resin. Differences in composition could be related to the nature of the resin, e.g. wax-containing (unrefined), bleached, or aged samples. Furthermore, differences in the relative abundances of aliphatic hydroxyacids appear to be associated with the biological source of the resin. The diagnostic value of newly characterised lac components, including 8-hydroxyacids, is discussed here for the first time. Identification of derivatised components was aided by AMDIS deconvolution software, and discrimination of samples was enhanced by statistical evaluation of data using principal component analysis. The robustness of the analyses, together with the minimal sample size required, make these very powerful approaches for the characterisation of lac resin in museum objects. The value of such analyses for enhancing the understanding of museum collections is illustrated by two case studies of objects in the collection of the Philadelphia Museum of Art: a restorer's varnish on a painting by Luca Signorelli, and a pictorial inlay in an early nineteenth-century High Chest by George Dyer.

Effect of Storage Methods on Quality of Lac - A Natural Resin

A study was carried out to assess the changes in physico-chemical parameters of lac resin during storage for one year. All three forms of lac viz. sticklac, seedlac and shellac were stored following different methods as practiced by lac traders and industries, and some quality parameters of the products were evaluated during storage. Qualitative losses included decrease in flow, heat polymerization time (life) and rate of filtration; and increase in colour index and hot alcohol insolubles of lac resin during storage. In case of sticklac, maximum increase in hot alcohol insolubles (24% in ari and 69% in phunki sticklac) was noticed in samples stored in plastic bags and minimum increase (4.87 % in immature lac and 37 % in used-up broodlac) was observed in samples stored on cement floor. Very little difference in the value of flow was observed between different methods of storage. Better life and colour were observed in products stored on earthen floor. Seedlac stored on cemented floor best retained the properties i.e. minimum increase in hot alcohol insolubles (6.17%) and minimum decrease in flow (35.89%) and life (13.43%) after one year of storage. Storage in metal container resulted in 87.65% increase in hot alcohol insolubles, 61.54% decrease in flow and 19.4% decrease in life. Flow and life of cold stored shellac samples were found slightly higher (2 to 5 %) than the samples stored by other methods after one year of storage.

Degradation of lac with storage and a simple method to check the same

PurposeThe purpose of this paper is to find out a convenient chemical treatment for seedlac and shellac (semi‐refined and refined commercial forms of natural resin lac, respectively) for preventing degradation during storage at room temperature condition.Design/methodology/approachSeedlac and shellac are treated with a dilute solution of an antioxidant before storage. This method has not been attempted before. The changes in the physico‐chemical properties of both untreated and treated resins are investigated periodically during storage.FindingsAntioxidant delays the degradation of seedlac and shellac at least by six to eight months during the early period of storage. It is further observed that oxalic acid, used in the trade during conversion of seedlac into shellac by hot filtration for imparting gloss on shellac flakes for attracting buyers), causes rapid polymerisation of shellac resulting in zero value (100 percent decrease) of flow (fluidity) within 30 months of storage, whereas, shellac prepared without treatment of oxalic acid could be stored beyond that period without a significant deterioration in its qualities.Research limitations/implicationsAntioxidants are known to be scavengers of OH groups. Lac resin (shellac and seedlac) contains five hydroxyl groups and one carboxyl group. Thus, only one dilute concentration of antioxidant is used to avoid possible modification of seedlac and shellac.Practical implicationsConsumers of shellac are not aware of the ill effect of oxalic acid treatment being practiced by processors. The results obtained in the present study will help consumers to advise processors suitably before purchase and will be able to store shellac for a longer period if it is not treated with oxalic acid. The consumers may also use an antioxidant to delay degradation of seedlac/shellac.Originality/valueThe results obtained in this paper, regarding the effects of treatments of antioxidant and oxalic acid are not available in any previous publication. These are reported for the first time.