Industrial Biotechnology

Milk is a complete food that cannot be substituted. However, the presence of various bioactive phytochemicals, absence of cholesterol, high energy input required for production, limited availability of milk in some regions, emergence of vegan diets, and limited resources such as landmass, feed, etc. are accelerating development of non-dairy alternatives. The present study was carried out to develop dairy analogs such as curd and kulfi by replacing cow milk with coconut and oat milk. Hydrocolloids such as xanthan gum, rice starch, and corn starch were used as stabilizers. As a sensory evaluation, 2% corn starch in curd and 1% rice starch in kulfi were used to achieve desired texture and stability. Yield ranged from 70–80%, which can be helpful in terms of production. All the samples were evaluated for their sensory attributes and physical properties. As the concentration of rice starch increased from 0–5% during kulfi preparation, the melting rate decreased and melting resistance increased significantly (P < 0.05). The work showed the potential of coconut as an alternative source of milk in making dairy analogs with improved nutritional benefits and acceptability.

Idli is a popular Indian fermented cereal-legume snack that is steam-cooked and traditionally produced with a fermented batter of rice (Oryza sativa) and dehulled black gram (Phaseolus mungo). The study's goal was to use aloe vera gel and aloe vera rind to minimize fermentation time, improve quality, and improve the idli batter. The bioactive components and physicochemical features of aloe vera gel and rind were evaluated on a dry basis. The optimized idli batter was analyzed for its microbiological properties and the leaching of soaking water of rice; black gram was investigated for growth kinetics. Panelists assessed aloe vera-incorporated idli samples based on a 9-point hedonic scale for color, texture, taste, flavor, scent, and overall acceptability. Samples with 20% aloe vera gel and 5% aloe vera rind concentration obtained the highest overall acceptability scores, 8.7 and 7.2, respectively, and were found to be the most acceptable in the sensory evaluation. As a result, it can be inferred that developing aloe vera-based fermented goods can minimize fermentation time while also improving nutritional, textural, and sensory properties.

Single cell protein (SCP) refers to dead and dried cells of microorganisms such as yeast, bacteria, fungus, and algae. SCPs serve as food or feed supplement and provide an alternative to traditional protein sources. This study aimed to produce SCP from Lactobacillus sp. using fruits and vegetable waste (orange peels, onion peels, and pea pods). The maximum yield of SCP produced was 8.6 g with inoculum of 4% at pH 6 for 48 h at 37°C on food waste media with a 1% concentration. The SCP was found to be rich in vital macronutrients such as protein (48.34 ± 0.05%), fat (2.44 ± 0.2%), fiber (2.97 ± 0.16%), and ash (5.93 ± 0.25%). SCP was also evaluated for its functional properties such as bulk density (0.62 ± 0.08g/cm³), water (2.31 ± 0.43 mL/g) and oil (1.89 ± 0.26 mL/g) absorption capacities, foaming capacity (12.25 ± 2.04%), emulsion (50.5 ± 0.99%), DPPH inhibition (38.84 ± 0.01%) and total phenols (10.19 ± 0.04 mg GAE/g)]. The results suggest that the SCP produced is rich in many vital micronutrients and possesses important functional properties, which suggests it is a potential candidate to be used as a functional ingredient in food products. Moreover, to the best of the author's knowledge, there is no report available in the literature on SCP production by Lactobacillus utilizing food waste. The conversion of food waste into a value-added product using the easily available and safe microorganism Lactobacillus makes SCP production more economically viable and environmentally friendly.

For mead production, honey wort must be supplied with nitrogen to avoid slow or stuck fermentations or the production of undesirable flavor compounds. However, supplementation needs vary depending on wort composition and yeast strain, and studies involving the supplementation of honey wort are rare, and there are no studies on recovery from fermentative failures through late supplementation. Thus, honey wort at 25.5°Brix was supplemented with di-ammonium phosphate (DAP) or ammonium sulfate (AS) either 1) exclusively in the wort at 0.7 g/L; 2) after 14 days (0.3 g/L); or 3) in the wort and after 14 days, at 0.7 and 0.3 g/L, respectively, and fermentation was carried out during 26 d by the yeast Saccharomyces cerevisiae JP14. Non-supplemented wort resulted in failed fermentation, and late nitrogen addition partially recovered the process. Nitrogen addition at both stages improved yeast performance, which allowed the production of meads with higher concentrations of ethanol. Volatiles' production was also improved when nitrogen was added, especially when AS was the source. Wort early supplementation generated meads with higher concentrations of isobutyl alcohol, acetaldehyde, ethyl acetate and 1-propanol, and lower 2-phenyl ethanol; the latter was not affected by late supplementation. It was evident that the timing for nitrogen addition, besides the nitrogen source, significantly affected ethanol and volatile synthesis during mead production. Therefore, nitrogen sources and the strategy used for their addition can be used to control the chemical profile and sensory quality of meads.