Development of edible tablewares and its quality evaluation

Abstract

The concept of edible tableware is a recent area of development to address the alarming situation that the excessive generation of non-recyclable plastic wastes has created. Non-biodegradable plastics are a major threat to the environment. The demand for green alternatives is increasing, the edible tableware is a new concept in which the utensils like plates, bowls and spoons are used to serve foods. Various composite mixes can be used for making edible tablewares. It is pertinent to mention that scanty data is available on the standardised protocols for production of edible tableware using cheaper and locally available food resources. Hence, the study is proposed to develop healthy and environment friendly edible tablewares with the following objectives, standardisation of edible tablewares using cereals, tubers, millets, fruit peel and rind, to evaluate nutritional, organoleptic and shelf life qualities and to enhance the qualities of developed tablewares with antimicrobial agents. The edible tablewares were formulated by using rice, wheat, finger millet, little millet, cassava, elephant foot yam, raw banana peel and jackfruit rind as major ingredients in combination with corn flour for the development of edible tablewares. Eight composite mixes combined with corn were prepared. Optimisation of binders, oil content, kneading time and temperature, and baking time and temperature were carried out. Organoleptic evaluations identified 5% gluten for rice based edible tableware and 3% guar gum for those made from elephant foot yam, finger millet, and little millet flours as binders. Oil content was optimized, with the best appearance and texture achieved using 5 ml of oil. Kneading time and kneading temperature was determined based on dough appearance and texture, and was fixed as 10 minutes and 34°C respectively. The optimal baking time and temperature were 180°C for 90 minutes, while for the fruit peel and rind based tablewares, it was 160°C for 90 minutes. Edible tablewares were prepared from rice, wheat, cassava, elephant foot yam, finger millet and little millet separately in combination with corn flour. Different flour was used in varying proportions ranging from 90 to 40 per cent along with 10 to 60 per cent corn flour. Edible tableware made from rice was optimised with varying proportions of corn flour. Treatment RT5 (50% rice flour + 50% corn flour) achieved the highest quality scores, with a total mean of 8.67. The hardness of these rice based edible tablewares ranged from 114.108 N to 156.712 N. For wheat flour based tablewares, treatment WT1 (90% wheat flour + 10% corn flour) recorded the highest sensory scores, with a total mean of 8.15. The hardness of the optimized wheat flour based tableware varied from 44.611 N to 98.705 N. Among cassava flour based tablewares, treatment CT4 (60% tapioca flour + 40% corn flour) achieved a mean score of 8.47 for overall acceptability, with a maximum hardness of 43.843 N. For elephant foot yam flour, treatment ET5 (50% elephant foot yam + 50% corn flour) received the highest mean score of 8.73 for overall acceptability, while hardness ranged from 52.427 N (ET1) to 67.761 N (ET6). Edible tablewares prepared from finger millet flour was optimised with varying proportions of corn flour. Treatment FT5, consisting of 50% finger millet flour and 50% corn flour, achieved the highest total score of 8.67. The maximum hardness of the finger millet flour tableware was 68.691 N in treatment FT6 (40% FMF + 60% CF). For little millet flour based edible tablewares, treatment LT5 (50% LMF + 50% CF) received the highest mean score of 8.60 for overall acceptability. The hardness of little millet flour based edible tablewares ranged from 34.616 N (LT1) to 97.563 N (LT5), with the highest hardness of 97.563 N observed in LT5. Edible tablewares using fruit peel and rind like banana peel and jackfruit rind were standardized. Two sets of edible tablewares were prepared, one based on raw banana peel pulp and another one based on jackfruit rind pulp separately in combination with corn flour. For the banana peel pulp based edible tablewares, the treatment BT5, with 50% banana peel pulp and 50% corn flour, recorded the highest total mean score of 8.47. The hardness of the banana peel pulp based edible tablewares varied from 23.914 N (BT1) to 46.773 N (BT5). For the jackfruit rind pulp, treatment JT5 (50% JRP + 50% CF) achieved the highest total mean score of 8.91. The hardness of the jackfruit rind pulp based tableware ranged from 29.624 N to 60.827 N, with the highest hardness observed in treatment JT5. Based on the organoleptic qualities and textural properties, the most acceptable treatment from each set was selected. The selected eight treatments of edible tablewares from each set (RT5, WT1, CT4, ET5, FT5, LT5, BT5 and JT5) were packed in HDPE covers and were stored for a period of three months under ambient conditions. The following qualities were evaluated initially and at the end of storage period. The physico-chemical properties of the developed edible tablewares indicated that the hardness of the selected edible tableware ranged from 45.653 N to 123.057 N. The water absorption index (WAI) varied between 4.11% and 5.66%. The water soluble index (WSI) of the selected edible tablewares ranged from 7.49% to 9.63%. The oil absorption index (OAI) ranged between 1.23 and 2.79 g/g. The cold water solubility among the treatments ranged from 52.77% to 69.14%. Hot water solubility across treatments initially varied from 70.16% to 95.26%. The pH of the selected edible tablewares were between 5.19 and 5.53. The moisture content in the edible tablewares ranged from 1.61% to 2.97%. The starch content varied between 50.42 g/100 g and 75.93 g/100 g. The fat content ranged from 6.24 g/100 g to 9.91 g/100 g. The protein content ranged from 8.77 g/100 g to 13.56 g/100 g. The crude fiber content varied from 1.77 g/100 g to 3.673 g/100 g. The total ash content ranged from 1.42 g/100 g to 2.04 g/100 g. The organoleptic evaluation of the selected edible tablewares were conducted during the initial, first, second, and third months of storage. Though the mean scores of all organoleptic parameters slightly decreased throughout the storage, all selected edible tablewares maintained an acceptable level at the end of storage period. The microbial population of the selected edible tableware was examined at the beginning and at monthly intervals for three months. Initially, no bacterial growth was detected. However, bacterial counts ranged from 0.02 x 10⁶ cfu/g to 0.43 x 10⁶ cfu/g in the first month, 0.24 x 10⁶ cfu/g to 0.61 x 10⁶ cfu/g in the second month, and 0.46 x 10⁶ cfu/g to 1.02 x 10⁶ cfu/g in the third month. No fungi were detected initially, after the first month and after the second month. However, by the end of the third month, fungi were observed in a range of 0.01 x 10³ cfu/g to 0.09 x 10³ cfu/g. Yeast growth was not found throughout the storage period. Insect infestation in the selected edible tableware was not detected throughout the storage period. The best treatments from each set of experiment I and experiment II were selected and were incorporated with antimicrobial agents. Curcumin extract was added to the base material of the selected edible tableware in varying percentages (2%, 4%, 6%, 8%, and 10%). Sorbic acid was incorporated to the base material in selected edible tablewares in varying percentage levels (0.02%, 0.04%, 0.06%, 0.08% and 0.1%). The edible tableware without sorbic acid was used as the control (T0). The organoleptic evaluation of the quality enhanced edible tablewares were carried out. Based on organoleptic evaluation and textural properties, from curcumin extract added edible tablewares, the treatments CRT3, CWT2, CCT3, CET2, CFT3, CLT2, CBT2 and CJT2 with total mean score of 8.61,8.53, 8.58, 8.67, 8.55, 8.49, 8.53 and 8.53 respectively, were selected for the further studies. From sorbic acid added edible tablewares, the treatments SRT2, SWT3, SCT1, SET1, SFT2, SLT1, SBT1 and SJT2 with total mean score of 8.91, 8.70, 8.15, 8.49, 8.40, 8.45, 8.67 and 8.55 respectively, were selected for the further studies. The selected treatments were packed in in HDPE covers and were stored for a period of three months under ambient conditions. The following qualities were evaluated initially and at the end of storage period. In curcumin extract added edible tablewares, the moisture content ranged from 1.65% to 3.08%. The starch content initially varied between 52.57 g/100 g and 77.43 g/100 g the fat content ranged from 7.17 g/100 g to 10.21 g/100 g. The protein content ranged from 8.98 g/100 g to 13.97 g/100 g. The crude fiber content varied from 1.94 g/100 g to 4.01 g/100 g. The total ash content ranged from 1.75 g/100 g to 2.97 g/100 g. In sorbic acid added edible tablewares, the moisture content in the selected edible tablewares added with sorbic acid ranged from 1.63% to 2.90%. The starch content of selected edible tablewares added with sorbic acid varied between 51.86 g/100 g and 76.92 g/100 g. The fat content ranged from 6.95 g/100 g to 10.05 g/100 g. The protein content of selected edible tablewares added with sorbic acid, initially ranged from 8.85 g/100 g to 13.77 g/100 g. The crude fiber content varied from 1.83 g/100 g to 3.01 g/100 g. The total ash content of selected edible tablewares added with sorbic acid ranged from 1.58 g/100 g to 2.13 g/100 g. The mean scores for the overall acceptability of selected quality enhanced edible tablewares were above 8.00 throughout the storage. The selected quality enhanced edible tablewares were evaluated initially and during first, second and third month for bacteria, fungal, yeast and insect infestation for a period of three months. The bacterial colonies were not detected initially. An increase in bacterial count were noticed after third month of storage in all the products. Fungi and yeast growth were not found throughout the storage period. Insect infestation in the selected quality enhanced edible tablewares were not detected. The selected quality enhanced edible tablewares were shelf stable without any deterioration upto three months of storage in HDPE covers. Microbial population was considerably low in edible tablewares added with antimicrobial agents. The cost for developed edible tablewares ranged between Rs. 30.50/ 100 g to Rs. 68.25/ 100 g. The edible tablewares developed in this study, as a sustainable alternative to single use plastic and these tablewares were nutritious. From the study, it is evident that highly acceptable edible tablewares could be prepared from locally available resources.