<?php
    WCVendors_Pro_Form_Helper::select( array(
        'post_id'       => $object_id,
        'class'         => 'select2',
        'id'            => 'wcv_custom_product_ingredients',
        'label'         => __( 'What time?', 'wcvendors-pro' ),
        'placeholder'   => __( 'Pick a time', 'wcvendors-pro' ),
        'wrapper_start' => '<div class="all-100">',
        'wrapper_end'   => '</div>',
        'desc_tip'      => 'true',
        'description'   => __( 'Pick a time', 'wcvendors-pro' ),
        'options'       => array( '12:00 midnight' => __('12:00 midnight', 'wcv_custom_product_ingredients'), '12:15 midnight'=> __('12:15 midnight', 'wcv_custom_product_ingredients') )
) );
?>

add_action('woocommerce_email_after_order_table', 'wcv_ingredients_email');
function wcv_ingredients_email() {
    $output = get_post_meta( get_the_ID(), 'wcv_custom_product_ingredients', true );
    echo 'What time? ' . $output . '<br>';
}

// Tested on WooCommerce version 2.6.x and 3+ — For simple products only.
add_action('woocommerce_email_after_order_table', 'wcv_ingredients_email', 10, 4);
function wcv_ingredients_email( $order,  $sent_to_admin,  $plain_text,  $email ){
    foreach($order->get_items() as $item_values){
        // Get the product ID for simple products (not variable ones)
        $product_id = $item_values['product_id'];
        $output = get_post_meta( $product_id, 'wcv_custom_product_ingredients', true );
        echo 'What time? ' . $output . '<br>';
    }
}